I am not epileptic per se, but I do have a seizure disorder, one that is completely controlled by medication. I can absolutely guarantee you that stress is a major contributor to the onset of seizures. Short of combat duty, there aren't too many positions that impose a more chronic level of stress than a head coaching job at a major college football program. It would, indeed, be in Coach Kill's best interest to find a less stressful profession.
Having said that, it can be frightening for observers to witness a grand mal seizure but they rarely impose serious risk to the patient, other than a lacerated tongue. Seizures of that type will leave you physically and mentally exhausted, however. For lack of a better analogy, they are the equivalent of a massive thunderstorm in the brain, one that discharges excess electrical energy via convulsions.