I imagine some people ‘don’t know about that’, but I’m quite sure 
. If they follow me out and basically accuse me of stiffing them which is what even the question means, I’m not going back. No disagreeableness from me on scene, not my style. But again I’m used to pretty much unlimited restaurant choice. Let’s even say it’s doing me a favor to not even bother me about their lost money (I don’t think so, but let’s say). Other of the innumerable places I can go to instead might extend me that favor. So why go back to a place that won’t? Again if it’s the only restaurant in town or perhaps it’s that unbelievably good IMO compared to other places…but that’s not such a realistic scenario for me (well not that the basic scenario is realistic either, why pay cash when I can get 5.25% back on the credit card?). Basically if there’s any discussion along the lines of, ‘no offense, and I’ll believe you if you say no, did you just try to steal from us?’. Not going back. YMMV, it would seem.
I can tell I’m on a left-leaning message board when, in a scenario involving stealing, “the thief” isn’t one of the poll options for assigning fault.
The poll option isn’t assigning fault, it’s determining who, at this point, is going to pay the bill. This is spelled out in the OP. It can’t be the thief because the thief has departed and is unknown.
If I’m the bartender, and I know they do this, I’m going to pick up the cash while the wife is still sitting there and say, “Thanks, have a great evening.”
Why do you feel that is a reflection of “left-leaning” politics?
Please read the OP and you will see why it isn’t one of the poll options.
The question was “Who is responsible for paying the bill?” Not who might have to. The only answer is “the thief”. Period.
If I leave my house unlocked and a thief absconds with my television, the ONLY individual who is responsible for the monetary loss is the thief. Not me, not society, not the insurance company. It may be that one or more of us has to bear the cost due to lack of options – but we are in no possible way “responsible” for it.
Perhaps this is a difference in semantics, or personal definition of “responsibility”. The first definition of the word I get on Google coincides precisely with mine: the state or fact of having a duty to deal with something. [bolding mine]
In both the OP’s example and mine of the unlocked house, no victim ever has a duty to suffer for, or pay for the actions of a criminal, although some may end up bearing such a loss through circumstance. Only the criminal bears actual responsibility for his actions.
I think you’re being unnecessarily pedantic. It seems clear that the actual question being asked is who might have to pay the bill.
The thief cannot pay the bill, though. If my mother in law soils the bedsheets and then leaves, and my wife says, “Who’s responsible for cleaning up these sheets,” the answer is not my mother in law. It’s either me or my wife. My MIL is responsible for the situation we’re in, but she’s not going to be the one cleaning up the mess, which is still a responsibility that exists.
I think you understand this and you’re trying really hard to make this political when it’s not.
You’re probably right. I have a very strong view of the word that probably is more strict than most. Perhaps I should lighten up on this.
This is similar to a heated argument I had recently regarding speed limits. Whether I (who adamantly follows the law) had a responsibility to speed up and ease traffic flow, rather than adhere doggedly to the published limits. I got hung up there as well, asserting that I have no “responsibility” to correct for the lawless behavior of others.
So to keep the peace, Bob should pay, and I’ll start driving faster. 
The way that Bob paid the bill implies a certain familiarity with the establishment, like Bob is a regular customer who has paid that way before. If he was not familiar with the place he shouldn’t have paid that way.
This would be perfectly fine in the local places that I haunt but I would never do so at an out of town location I was not familiar with. At my local place where ‘everybody knows your name’, I routinely leave cash, my cell phone, my car keys, on the bar and do not worry if I leave them there when going to the restroom. I will be taken care of.
So my answer is that the restaurant is responsible. They are responsible for the safety and security of their customers and their articles while the customer is at their establishment. They should take care of the bill unless they really think Bob is screwing them. But they know Bob and he wouldn’t do that. Either that or Bob is a complete idiot and out of his element for trying this payment method in a strange place.
The hypothetical situation is sort of a moot point anyway since even the smallest shops have cameras, not just to watch the customer, but the employees too.
The thief is responsible. Bob may have been better off waiting to be sure the waitress got the money, but ultimately the restaurant has a theft problem. The thief could just as easily be stealing tips.
Yeah, I wonder how many people who voted “Bob” here stick around to personally hand (cash) tips to the waitstaff to prevent theft. I think leaving a tip on the table and walking out the door is even more common than leaving the full amount on the table and walking out.
In college once, my friends and I were chased in the parking lot by the waiter asking us where the tip was. We had left it on the table, as we told him. Perhaps someone stole the money.
So Bob gets chased down. His options are to pay for it or not and if not the waitress can call the cops.
If I’m Bob from a practical point of view I’m paying. But I’m also never going back there again so everybody loses (other than the thief).
Yeah, I don’t patronize restaurants where tip theft is something I worry about.
That’s just part of what they say, it’s what they’re trained to say. They are assuring you that they’ll be right back to collect your credit card or take your cash and bring your change back. As in “Don’t rush, I’ll be right back to get your payment”. With that, it’s accepted that if you don’t need change or anything further from the waitstaff, you can leave.
Similarly, when they collect your money (if it’s cash) they’re taught not to say “Do you need change”, but rather “I’ll be right back with your change”. If your bill is $22 and you put down $30 and she says “Did you need change?”, many people may feel obligated to suddenly leave much larger tip than anticipated ($8 instead of 4 or 5). Your total could be $25 and if you leave thirty, they should still tell you they’ll be right back with your change.
I don’t think we’re missing anything important. I feel like you’re not understanding how this practice works. It’s the basis for the entire question. It’s just how things work in restaurants.
To mention an example from earlier in the thread, if a waitress hands you a bill, walks away and a few minutes later sees you leaving, she’s not going to think anything of it. If you go to home depot, pick up a $5 hammer, toss $10 at the cashier and head for the door, you’re going to get stopped.
Besides all that, if her saying “I’ll be right back” is what puts all this on Bob, then if Bob replied “you can keep the change, thanks”, it would be her fault because he told her (or implied to her) that he was leaving the money.
I think quite a few people are working from the OP where we have perfect knowledge that Bob paid, but in the scenario we don’t have that knowledge. If they were actually in a restaurant and they witnessed a scene between a guy and a waitress where the guy was insisting he left a 20, the waitress there was nothing there and nobody in the place had noticed anything untoward, I expect fewer would support Bob, mostly assuming he was a chancer who got caught.
Of course the restaurant is on the hook if we have any evidence at all Bob paid
Bolding mine.
What? You’ve never seen a sign in a restaurant that says something along the lines of “Not responsible for lost articles”?
The person responsible for paying the bill is Bob, but in your scenario, where Bob really did put the money down, he paid the bill. He’s not responsible for paying a second time, which is what you’re really asking about. Bob paid the bill in a commonly acceptable way; someone else stole the payment.
The waitress might not believe he paid, but in the scenario you laid out, he did.
Also, I’ve been to many, many restaurants where I left the money on the table because I’d been trying to get the wait staff’s attention in order to be able to pay, and eventually just gave up and left the money. Seriously, I’ve spent half an hour trying to pay and leave. Take my money! I want to pay you!
A few times we even gathered up what cash we had and put that down rather than paying by card because we had to get on to somewhere else and the waiter/waitress simply wasn’t coming to take the money. And this was at sort of mid-scale restaurants - they’re the worst for it.
This might be more of a problem in the UK than the US but it’s fairly common, or at least was about ten years ago when I was last eating out regularly. One of the worst was a special pre-theatre meal (tied in to the show) where they delayed so long we missed the first half.
So it partly depends how much effort Bob made to get the wait staff’s attention to pay the bill before he threw down the money and left.
It also depends on how Bob left the premises. Once as a teenager I accidentally left a cafe without paying, and the waitress caught up with me. I was very embarrassed, but she genuinely didn’t think I’d been trying to stiff her because I’d strolled out, and walked at a normal pace to the crossing opposite the cafe and waited to cross, and didn’t seem upset about seeing a woman from the cafe. I returned, paid (and had the cash to pay for it, which also indicated I was intending to pay), and nobody acted like it was me trying to stiff them - sometimes people are just inattentive. If I’d claimed that I’d put the money on the table they probably would have believed me. As a waitress I’d have reacted the same way.
If Bob put on his coat, checked his pockets, and walked off in a normal way, then claimed he’d left the money, he’s either a hardened and practiced non-payer or someone who actually did pay in a way that’s socially acceptable in that establishment. If the waitress catches up with him then odds are he’s not a hardened non-payer because he’d have put some speed on once he was out of sight.