I've noticed it in several of my games as well.
I think when vehicles hit a mine that in turn immobilizes them (as in your Stuart tank case) they coast forward due to te momentum buult up from the speed they were travelling at the time.
Since your Stuart was moving at "Fast" speeed and it's fast speed is quite high for a tank. I'm not surprised at the distance it's forrward momentum has carried it.. :-)
Highly unrealistic IMHO, if a track blows it's either going to come to a grinding halt or spin off to one side as one side stops but the intact track keeps going, same applies for bogged, if its bogged generally it's stuck!