Actually, I’m a Jewish person, from Syracuse NY, and I failed my bar mizvah five times in a row! I have a terrible lisp, which doesn’t complement well with Hebrew. But in the end, the rabbi was good humored about it, although he was sometimes a bit upset he had to constantly clean his glasses.

It's not a test, it's a ceremony. The boy in question is expected to read several passages from the Torah, but there's no penalty for doing it poorly or not at all.