What if it IS what my character would do?

[Rater202]

This. Blame is not conserved, multiple people can be 100% at fault.

Yes, sometimes.

But not in the scenario I described.

In this scenario, the GM made design to change the rules of engagement for the campaign midway through while giving neither hints in-game or statements in real life that the rules had changed. The player who continued to act the way they acted the entire game with no complaints bears no responsibility for the fallout. It s not like he can read the GM's mind.