I googled around a bit, and found some support for this, but also some suport for alternate theories. If you think about it, it doesn’t make much sense, as “being left holding the bag” doesn’t mean “being the one who is the most embarrassed”, it means “being the one left to take the blame”.
Your source isn’t convincing to me. The lewd explanation makes more sense, absent strong evidence to the contrary. The fact that barrels were used as first aid for drowning victims doesn’t detract from other (ahem) uses to which a barrel might be put. Nor does a drowning victim make sense as a metaphor for someone who is about to get, well, screwed. A much better metaphor is someone who is literally about to be screwed.
The “one left holding the bag” in snipe hunting is the one who got suckered and received no benefit. Which is how I always understood the phrase. Naught to do with blame. It’s the one who was left out of the game and winds up looking the fool.
(Say, are you trying to become my phrase-origin nemesis? 
)
Upon closer reading, it appears that your source doesn’t buy the drowning victim origin either, but points to a single recorded instance of a student being hazed by being rolled while tied to a barrel.
Still not convincing to me. The lewd origin makes more sense. It would also explain why the Woodland Daily Democrat seemed embarrassed to use the phrase in 1896. From your source:
I use to think several meant 7 and only seven.
Sorry for the multi-posting, but this site suggests that “over a barrel” might be a spanking metaphor, and points to this bit of verse from 1869:
Now that makes sense to me. So maybe it’s not lewd.
The song, “I never picked cotton” seems to back this up. Roy Clark, who as far as I can tell was the first to popularize this song, is not black, and the context is clear that his family, with the exception of his father, picked cotton so I don’t think it is referring to race. The song does make it clear that picking cotton is an unpleasant task.
Piccadilly Circus is not named for a colorful gathering of tents containing elephants and bears and clowns and whatnot. In fact, that meaning of ‘circus’ came from the shape of the tents, which were in fact circles or, if you’re a fan of Latin, circus.
Here is what the word detective says
The word detective just looks wrong on this one. First of all, the drowning victim doesn’t make sense as a metaphor. Someone about to be spanked or flogged makes a lot more sense as a metaphor.
Moreover, the word detective cites “The Big Sleep” (1939) as the first usage of the metaphor, whereas the newspaper cite I mentioned above (taken from MaxThe Vool’s link) is from 1896, more than 40 years earlier. And the poem suggesting that spanking is the origin of the metaphor is from 1869.
Spanking still makes more sense.
The word detective is all wet. (Tee hee.)
According to my parents, cotton husks have very sharp edges, which were apt to slice up your fingers and arms. Because of this, pickers tended to wear long-sleeve flannel shirts to protect their arms. So you get the misery of cutting up your fingers on the husks, combined with the misery of wearing a flannel shirt in the searing Southern sun, combined with the misery of being stooped over all day, dragging a long cotton sack along the ground.
This bring back the charming brit vernacular of " It’s forty five past the hour." My brain went, " Whaaaa…" oh. she means quarter to.
Not sure if it is regional or just my brit friend who does this.
I used to think there was a word in-dict that people only used in print and a completely separate word en-dite that people only used when speaking.
A sonic sequence also known as “bada boom bada bing”.
That seems to me like a perfectly normal way of putting it. 45 past the hour? Yeah, I don’t see the problem with that. I’d use both that and quarter to interchangeably. I certainly don’t think it’s a British thing.
Me too - it was obviously the past participle of misle. I still think it sounds better 
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