Fair enough. And, I think that's the point that people are trying to make. There's a mistake that's been made at some point before the die roll. Somewhere along the line the DM messed up somehow. The DM didn't quite understand how a given monster works, for example (not an unreasonable mistake- there are a LOT of monsters) and suddenly finds that what was supposed to be a fairly low key, fun encounter, is now going to completely throw the game off rails and it's not going to be fun.
Like you said, if 6 werewolves is the random die roll for that 2nd level party that doesn't have any way to hurt the creatures, at that point, "carry on accordingly" might easily be "oh, I didn't roll that, let me roll (or pick) again" without telling the players. Fudging by the definitions used in this thread, but, entirely understandable.
Let's be honest here, D&D is not a simple game. There's a ton of stuff that we misunderstand, flat out miss, or misread. It happens. I'm fairly confident in saying we've all done it. So, when it happens, there's a perfectly good reason for fudging a result.
Like I said earlier, fudging is a fairly nuclear option. It shouldn't be your go to, first option when things go a bit sideways. It should probably be only used as a last resort, presuming you're playing a game where the math of the game is fairly well thought out. But, it's just another tool in the box.