my friend took a big as bong rip then stood up and blew the hit out the window. then next thing i see he slumps down with a thud and is kind of sitting on my desk(guess thats what kept him from falling right on fucking over) from my point of view, i couldn't tell what was going on in tell he comes to and says he had a massive head rush and passed out. i think thats what might have happened to your friend.

ps he didnt have much to eat and was hypoglycemic i think that contributed