Yes, you are leaving it out. Not to say that it isn't entirely reasonable that he could have been planning to leave unrelated to his own conduct at the company, and coincidence is just making him look bad in this scenario. It may look bad at a glance, but that doesn't automatically mean it is. It also doesn't mean his move is necessarily unrelated, frankly we just don't have enough information to do anything other than wild speculation with regards to him (unless someone actually has some specific information about him).
I'm not going to condemn him nor assume he is innocent, because I lack sufficient information to support either conclusion. Both seem possible, I have nowhere near enough facts about the situation to make any sort of reasonable judgement on it. So I'm withholding judgement until more facts become available.