Sometimes I can tell when my current DM fudges a roll to miss an attack or reduce damage. He has a tell in the specific way he pauses and breathes before announcing the roll, then tries to hurry to the next turn, which only seems to happen when someone is in a life-or-death scenario, but “luckily” survives.
Should I let him know he has a tell? Will it be less fun (or more stressful) for him if he knows I know?
If they want to pretend they’re not doing it, sure, I’ll pretend I don’t see it. If I think they’re fudging the dice too much, and it bothers me, I might bring it up with them privately, or I might suggest a group discussion, or I might just leave.
In general, I try to evaluate a GM as the whole package, rather than just the individual choices they make. If I like their campaigns, there’s no point in picking on individual decisions (beyond obligatory mild grumbling, of course, lol). Sometimes, they’re going to get results using techniques I wouldn’t choose, which is fine. If I don’t like their campaigns, there’s still no point in picking on individual decisions. I would rather drop out as soon as I realize something isn’t working out than stick around, lose my temper, and say something I will regret.