We've already had a look inside his head, because he joked with his friends about how naive the people giving their information to him were for trusting, and how they were dumb fucks that he looked forward to fucking in the ear.

Sure, he might have changed since, but there's nothing wrong with rational speculation. Selfishness and greed are real phenomena in human relations so it would be as foolish to ignore such possibilities as to believe them uncritically.