FLAK CAN HURT TANKS TOO..:)
Here, my test proves that a single German 20mm flak can immobilise a KV-1, force its crew to bail, and also damage a KV-1's gun.
1 - The flak immobilises the KV on only turn 1
2 - Confirms it really is a 20mm Flak
3 - After peppering the tank for more turns, the crew bail on turn 6
4 - In this separate test the 20mm Flak damages a KV's gun on turn 3
PS - I already knew all the above anyway because I've had tanks immobd and suffer damaged guns in actual games, so the tests were just to convince the unbelievers out there..;)