You are correct about the 100ms (although 5s is too short, should be something like 30 given our understanding of task switching) but it's worth pointing out that the comparison you quote (and all those like it, not just from Tesla) is disingenuous.

All the self driving companies do this, but it only makes sense to compare # of accidents/mile between like processes. It's an ok proxy for total risk iff accidents were uniformly distributed, but we know that isn't even close to true.

With a system like Teslas', it is preferentially, probably approximately exclusively if normalized by distance, deployed in situations with a lower accident rate - comparing that to total rates is nonsense.

What would be more interesting is Tesla vs. human accident rates on only freeway miles, say, but I haven't seen that anywhere, have you?

Best rough stats I can find is that less than 1/2 of all accidents happen on highways. There are a also a ton of fender-bender, parking lot and/or traffic jam accidents that aren't really applicable either.