The only limit I've ever had is 5 over. I'm not 100% what roads have the limit and which don't (I mean the official position). For me, on AP1, I am always restricted on 2 lane roads. I'm never restricted on interstates or 4 lane roads with a median. It seems if there's a 4 lane road with a turning lane between, it always restricts me. But, I can say for sure.
Maybe it did kick in but it was too late to significantly slow down a car.
Again, running (or at least almost running) a red light is the easiest mistake to make on AP in my experience (stop sign same thing).
I hope we never know TBH.
BTW - do you own or regularly drive a Tesla?
AP 2.5 here, and unless it's a freeway (or very rare errors in the speed posted), mine will only go 5 mph over the limit.
"Speeding" in the police report almost certainly eliminates AP.