Bitcointalk really needs two-factor auth at a minimum these days, and it looks appears it was a very savvy exploitation of previous PM messages to socially engineer a false transaction.
I'm not sure about that. Since the signature really does verify, it means minerjones was in possession of the XMR address in the message, and it appears the funds in question were sent to that address.
We don't actually know what happened without MJ's input. Am I missing something?