I once was in a very similar situation to that of Castile. The police mistakenly suspected me of just having broke into a house. When the cop wanted an ID, I like Castile, was trying to cooperate when the cop started to yell at me not to reach for my back pocket, but the innocent, non-combative mind has a hard time switching immediately from the fulfillment of one instruction to another and I completed pulling out my wallet. Thankfully in my case, the officers were well-trained and had a much more stoic demeanor than the officers who shot Castile and Damond or I would not be here either.
Exactly. Had a similar situation...my mind worked that way too.