If someone attempts to enter a vehicle leaving the bay, the vehicle seems to stop in place. This seems to be a more likely cause to vehicle destruction than timing. It's easy to mistake a tank as your own, try to enter it, and then watch your tank blow theirs up because it stopped in place.
Edit: You can see a guy backing off from that mammoth in that video, too. He likely attempted to enter the mammoth, realized it wasn't his, and backed off, only just to watch it explode in your face.