- He is afraid of beeing found when he spends one satoshi
- He forgot his wallet passwords
- The harddisk with the wallets crashed
- He is dead
(Most likely in that order)
I think he would have more than one harddisk with the wallets. He's either dead or not deleted the keys, if he was going to spend the coins he would have already.
it would have made sense to give Gavin a backup? lol .. who knows