Unless the folks who opined that the FA's actions were unwarranted were actually present - I don't think it's fair to make the judgement that that she/he overreacted.

You're only going by what the OP has told us. Who amongst us can say with any certainty how it went down?

Every story has at least two sides. I've seen passengers behave in an incredibly rude manner and instead of being written up probably should have been shot.

Perhaps the FA was showing restraint...