That's the part I just don't get. Everyone is focusing on the OPs mistake, yet the vast majority of those same people seem to put no blame on the FA. Why is that? I can only guess, but maybe they don't think that FA's have any responsibility to react accordingly.

The airlines and TSA are all about making examples of frustrated and, in this case, inappropriately behaving pax, but the same can't be said in reverse.

The old motto that the customer is always right is unknown in the commercial air travel sector these days.