Right, it was the damage done on deflect that was removed, not stun chance. Strange, I've never actually seen (or can't remember ever seeing) an IS2 stun a tank on a bounce. Maybe because it fires so slowly and the shells, when they do hit, more often than not penetrate what they hit?
AFAIK only the Brumm, IS2, ISU, and Tiger have the chance to stun crew via deflects. Stugs, Paks, and other assault guns stun 100% of the time with the Vet 1 ability only- unless you're saying your opponent had a Tiger and a vetted Stug chain-stunning the IS2, in which case that's an unfortunate fact of life.
I'd be happy with the complete removal of the whole deflect-stun thing in favour of a proper stat buff or cost drop. At least that way you get what you pay for all the time.
Yup, he had a vet Stug, but the first stun was by the tiger. Then straight after the stug's ability was used (nothing wrong with that - kuddu's because very few people use it) and then the 3 shot of the tiger in the saga stunned the IS2 again... By this time it had a sliver of health as the tiger moved in behind the IS2