I've watched 14 minutes into the video so far, and it seems like he was projecting all his life events and feelings onto a conspiracy theory, which is a common occurrence in people down these rabbit holes. For example, if you drop out from PHD of course you will feel like your life will go on a momentary all time low and all the people around you are making fun of you, it's what comes to quitting anything in life: jobs, projects, studies, etc. It doesn't have anything to do with reptilians whatsoever, it's an experience almost every human has to go through.
And by looks alone, he is the kind of kid you would joke around being a school shooter, because he is incel and visibly schizoid/mentally perturbed. That's why his friends were mocking him.
