Did Butch commit suicide by cop?

No. He was merely trying to give something to Philip (a photo maybe? I forget), and likely didn't realize there was a sniper far away with his finger on the trigger. At that point of the movie, Butch had lost a LOT of blood, and was actively dying. There's no way he was able to comprehend that his sudden movement would cause the sniper to fire at him. He was only able to process what was directly in front of him. Plus, Red was out there talking to him. The sniper didn't know the context of what was going on, saw Butch reaching for something that could have been a gun, and killed Butch.