(When he says the infamous "couldn't God be in the 95% that you don't know" most of the audience laughs. I really hope that at least some of them laughed because they realized how bad of an argument from ignorance this is.)
Sounds to me like they are laughing in agreement. The story is either completely made up or he was not understanding their reaction and just believing in his own head that he converted anybody. This is similar to a Chick's Tract where a kid challenges a professor who says there is no god and the kid comes back with questions like "does darkness exist?" and answers it himself saying, "darkness is just the absence of light", eventually leading to a "we don't know" argument. The professor gets all red in the face, in the real world, it would be pretty simple logic for any professor with any philosophy training.
This guy exposes his weakness more than most do when he repeats "if those were your only two options and both were believable". There are infinitely more options and the option of a loving god that has a room for you in heaven is not believable. There are thousands of other gods to choose from, and infinitely more that could be imagined. Heaven stopped being believable sometime around when Galileo could see beyond the clouds and just saw space and rocks. Actually, it was never believable, but I can at least understand how people were tricked into it before that.
So, he presents an argument from ignorance, gives you a false dichomoty, and admits it is a false dichomoty, then presents Pascal's wager. His communist audience didn't interrupt him, probably because they were just fascinated to watch him make this ridiculous argument and his audience in the video had already made their choice. So, he could just go on a roll about how great god is at that point.
This is the place all preachers want to get to. That point where they can just bask in the glory of god and expound on how wonderful he is and how his creation is just for us and how much better you are because you believe it and who wouldn't want to make that choice?
Of course, there is that one requirement, that you do make the choice. You don't get any of the benefits if you don't accept the choice without any further evidence. The irony is, by taking the choice of living his life as if this is it, this is the only shot you get, he misses out on living a full life in the real world.