I would have considered "pathetic" to be more insulting/innapropriate, but it's possible that I don't understand the meaning of "schmuck". I thought it was "an unpleasantly excentric person" but perhaps it's rooted in some vulgarity.
It does have a specific meaning in Yiddish, but it serves as a less offensive term in general English. I am am English speaker.
Still, it was used in haste and under a misunderstanding fo the situation.