Cell phone texting while driving maybe?
‘Texting’ could explain the first but not the second accident? The police didn’t seem to think distraction of that sort was a factor. It does fit perfectly what would happen with a series of TIA’s (they often come in waves). As he was walking back to his car from the first accident, he most likely had another attack. He probably didn’t even remember the first as he barreled off to the second one. Mind is really collective memory. You can’t form or hold memory if your blood supply to the brain is choked off, even transiently. The fact he got out of the car at the first accident scene shows he did not have much of a consciousness of guilt or a disposition to avoid responsibility.