Imagine a motorcycle cruise entitled “Mount View Annual Reunion, Ghost-of-Tickets-Past Appreciation Ride”. Out of state clubs welcome. June 1st through August 30th. Hours of ride Midnight to 8am.
Probable cause for what? 
I really don’t get that part.
Possibly probable cause to give you a ticket, because you have admitted (more or less) that your bulb was burned out. I doubt he would have probable cause to search your vehicle. Sort of like when they say ‘do you know how fast you were going’ and you say ‘around 70’ when the speed limit is 65.
For better or worse, you probably are not going to beat the ticket because the cop said he had probable cause. Unless you recorded the interchange, and the judge really cared about the exact wording used. If they are just generating revenue, they just want the money. Maybe you can bargain it down, maybe not. Maybe it’s even an injustice.
It’s one of those petty annoyances where they are counting on it being more trouble than it’s worth to fight. Pick your battles. As mentioned, it’s out of town drivers vs. everyone in town who gets the revenue. Is that unfair? Sort of. Should it happen? Maybe not. Can you do anything about it? Maybe. Go ahead and stand on your rights, if you want. You might even win. But probably not.
Regards,
Shodan
I viewed the cop saying he had probable cause meant the bulb being out gave him cause for the stop.
The cops don’t need probable cause to stop you - just reasonable, articulable suspicion. Which the cop had.
It depends on the state if that would constitute probable cause to arrest. I suppose that is up to the discretion of the cop.
Maybe the cop was just wrong about the correct phrasing, as I might be (IANAL).
But you are probably right, and the cop meant “now you have admitted that the stop was justified because the bulb was burned out”.
Regards,
Shodan