I'm a bit sad that it seems to be just a crit that turns it decrewed in the same manner that a pak is decrewed. I would've liked it more if you could decrew tanks manually and get a tank crew unit that can carry on the veterancy if they cap another tank. Would take some balancing of the vet ( a great scout car crew doesn't = vet 3 tiger for example) but I think it could've added an extra layer to the game.
I can partially understand it from a mechanics point of view. Not only does it add "clutter" to the game but it could also punish a losing player so when they lose a powerful unit they also gift it to their opponent which puts them even further behind.
I still think throwing grenades into open topped vehicles would be cool though!