Some insight from someone who's actually had seizures:
I just wanted to put in my $0.02 on this topic, because it sounds like there’s a lot of confusion (no pun intended). Nothing in any of the statements put out so far is at all inconsistent with Bryson having had a seizure, and I speak as someone who’s had a lot of them. It’s entirely possible, in fact, that he wasn’t genuinely conscious when he talked to the people at the first accident and then drove off. I’ve had seizures when I “woke up” to find myself half-carrying on conversations with people while walking, and once got onto a bike during a seizure and rode for quite a distance before recovering and being suprised not to find myself in the house, where I last remembered being.
I think people tend to only think of seizures as the convulsive grand mal (tonic-clonic) type, or sometimes petit mal (blacking out), which is not at all true. There is a huge range of different things that can happen when your brain screws up.
Also, very often the first part to go when a seizure starts is the part of your brain that lets you recognize when you’re incapacitated and the need for urgency, so even if you realize something is wrong you think you can make it just long enough to get to a safe spot…