This thought occurred to me, too - it would be the only thing that would give Snape's regret enough credit to stand alone as the reason why Dumbledore trusts him. (Although I'm willing to bet there are some HP fans out there that would think it more likely for Snape to have fallen for James
See ya,
AnnaBtG. (who loves all the speculation, but still hopes that JKR will manage to surprise her in Book 7)
