if haz is scum with TGT, tgt knew from jump there was a role thief in the game. Scum now has to bascially always be truthful about roles otherwise they run the risk of getting outed if someone flips wrong or if a role thief strikes again.
its possible, or it's possible that diana can do it multiple times and left that out. Scum has to be aware of that possibility at least, otherwise they hand out a free red check with 2 members remaining.
if towns gonna lie about roles, it's pretty much always vanilla vs not. Scum gets power safe claims as well as usually has powers that would never pass a role thief check, so they have to lie about powers.