OK, I’m not a doctor, but have some experience, as I have had a couple of seizures. That was a seizure, the main thing I remember from it was the feeling of moving my feet trying to stay upright, which is exactly what she is doing. I have also seen people pass out from heat stroke, and they don’t go stiff, jerk around like she did either. By the way it was 82 and 42% humidity!
I had two seizures in my 20’s, after a bunch of test, nothing was found, and the next question was if I had ever had a concussion. I had at least four concussions as a kid, so they just labeled that as a cause, and put me on dilantin for years. I slowly weaned off it about fifteen or twenty years ago with no problems.
I also am not too sure that alcohol abuse doesn’t have something to do with it, as when mine happened I was in my 20’s and something of a party animal, never out of control, but hit it hard. That probably applies to Hillary too!
Seizure can absolutely be attendant upon withdrawal from very heavy drinking.