thanks for posting that pic....looks a bit suspicious. Even after 1 bomb went off, others could be placed (that didn’t detonate).
I believe he was one of the LE that had the tan pants on and backpacks. I read they had chemical sensors in the backpacks and if so then he might be testing the air around the explosion site. (you saw the pixs of the two guys with the tan pants, black backpacks, and one was wearing a wire going to his ear, some said they were Navy Seals)