Speed is relative, I wouldn't call 25mph slow, to put it in perspective, he claims he was travelling at 36.5 feet per second, which is, if you think about it, pretty fast, especially if you think he went from 25-0 mph in about 2 inches.
A Car is a Linear Spring, Crash Test Investigators have had the Formula's for Decades to calculate how fast a Vehicle was moving, they probably won't go to all the expense unless Attorneys get involved, unless anyone was injured I doubt that would happen.
But who has time to look down at their Speedo while heading for another Car ?
But I guess the bottom line is, your RR held up really well considering a Jeep is a heavy Vehicle.
Sorry this happened, at least it sounds like you're all OK !!