I would have heckled the rabbi too. I have been to a similar such event, this time sponsored by AIPAC, where the "moderator" censored the audience questions and only allowed softball questions to be asked. It is infuriating and disrespectful to the audience when this kind of thing happens.
As to the documentary #Israelism, I have seen it and it is thought-provoking. It is sad that there couldn't have been an actual discussion after the film
https://forward.com/news/573561/rabbi-andy-bachman-israelism-hunter-college-erin-axelman/