My friend "fainted"? Paramedics?

I have a phobia of fainting and I've been trying to find out a lit about it as I have a heart condition and that is my biggest fear. My friend, who lies a lot, left science class because he said he didn't feel good and I went with him. We were burning metals. And as we both got up to go back inside, I caught a glimpse of him from the corner of my eye fainting. I can't tell if he really did or not. Looked odd. How do paramedics tell if someone's really fainted?