Lol talk about a complete fluke.
I had one of those on my GW Tiger a couple of days ago. The Swamps map, on the other side of the map was a Jagdtiger against our IS-4 both on critical, on my side of the map was my GW Tiger and a VK45 approaching my position and the flag.
I'm reloading an AP round as it turns up, shoots me, I survive, turn and point at him just as I reload, fully open aiming circle, AP round hits it square in the side and blows it up in 1 shot, then the IS-4 finishes the JT and we won the round.