I created a hypothetical situation where the person saying "it's what my character would do" is a valid defense: IE, a situation where the player saying that is objectively not responsible for the disruption. the GM is.

If you want objective facts, however, here's another example. This one actually happened.

I was in middle school, fourth edition just came out, I played my first ever evil character, an "evil" aligned tiefling fiend pact warlock. As an evil PC in a good party, his malicious schemes were mostly limited to background details. I'm pretty sure the worst thing I ever did prior to this incident was aim to put down an animal after we'd killed its master when another pc wanted to take it as a pet.

In an early session, we found a tomb buried under a stone that had the symbols of three good-aligned god carved in it and an enchantment that I was able to identify with an arcana check to be the kind of Juju that doesn't keep something out but something in. The GM told me that it was something serious enough that fear would be the appraite response.

Despite sharing this with the rest of the party, they pushed on and went in, taking an puzzle box from the tomb and pressuring my character to try opening it.

The other PCs tried and failed to figure out the puzzle to no consequence, but the GM pulled me aside and told me that since my PC was evil he'd developed an obsession with the box and trying to open it and, furthermore, told me out of character that one of my character's in-game goals could be achieved if I got what was inside the puzzle box without specifically telling me what it was, and honestly, out of character I started to get curious.

So, naturally, I roleplayed my character as being obsessed with the box, trying to open it at any opportunity, to the point that the other PCs wouldn't let me handle it without supervision... Note, my PC only tried to open it in the first place becuase I was pressured by other players in and out of character, initially my character wanted nothing to do with it.

Then, after combat when the other PCs were distracted and attention was drawn to how the box was hanging out of another PC's bag... I succeeded on a sleight hand check and absconded with the box.

I was caught in a back ally trying to open the box... Overpowered by the other PCs, dragged to a church, had the compulsion to open the box purged, and my character was made physically unable to lie as punishment for stealing the box(this was entirely a call by the GM and IIRC the other players didn't even know about the compulsion) while the other players all got angry at me out of character for stealing the box.

"It's what my character would do" is a perfectly valid justification for that, though not one I made becuase I knew it was used exclusively by jerkfaces in the olden days. My character was supernaturally compelled to keep trying to open the box and an opportunity was almost literally shoved in my face.