"Oh Shit" moments...

If he came to you 'very contrite' why do you think it was deliberate? It sounds like ineptitude on his part rather than aggression to me, so hopefully a useful lesson learnt on his part, particularly with having to explain himself to the police.

My immediate reaction was that it was a prank that went a bit wrong but I'm more inclined now I'm thinking a bit clearer to think it was as Wrongcog said - phone etc.

Don't worry, as long as your life insurance premiums are getting paid they won't mind ;-) (but seriously its not that dangerous statistically for the average rider....)

Don't think I'm particularly inept or risk prone - maybe the difference between fast rural B roads with not so much but very fast traffic and busy but slower urban?