It turns out that the guy who had the seizure at my gym has epilepsy and had recently had a change in meds. Evidently the new meds weren’t working. He was released from the hospital the same day as his seizure. He didn’t break anything, but is very bruised.

The folks at my gym have taken this incident very seriously and are installing AEDs at all of the branches and putting everyone through advanced training in CPR and the like. Hopefully, they will never need to use the stuff.