I can't explain it, but it seems like the younger the people are, the more instinct than other adults. It might be because they have not had as long to deny things when something is obviously wrong. Your student who was an EMT was trained and had a trained eye. I have always been taught to never put anything in the person's mouth, but put him or her on the floor and on their side and to let the siezure run it's corse, while calling 911.
I have wittnessed grand mal siezures in elementry school and it shook me up. I came home in tears and said he had a siezure again. I wittnessed a drop attack and got help because I could not get her up from the floor to the bed(I was working at a camp for disabled adults). That was scarry to, but I knew better how to handle my emotions.
I'm lucky I don't have siezures as much as has happened to my brain(hydro, a tumor wrapped around my brain stem, and a thiest in my cellebellum).