Please note: the tank is not a carcass, yet I am in the "back to garage" mode. The turret was still movable and could be seen to move by other players. I got no messages about the crew being killed, I was just suddenly on this screen. Though not entirely useful for me it was useful for the my team since at least two tanks obsessed over trying to kill me and were killed by my team in the process.
I saw something like this on a Stug earlier in the day and just assumed it was the dead crew thing. If my crew was dead I never received any sort of message and I had one of the reusable multi function repair kits in consumables.
Also note that the opposing tank is lit as if targeted.