Local users groups are good places to get decent critiques of your presentation before you take it on the road (bigger conference). The people are generally local and you've seen them before. Smart critiques are good for you and your code. I cannot imagine having audience participation banned at an user group.
The problem here is that and "outsider" came in and basically took apart a presenter brick-by-brick. From the writing of this one side, it seems like the presenter was trying to articulate a concept.