When Danyael is showing off for the kids with the chair, there's a shot of his head and neck. The collar of his shirt is lifted a couple of inches off his neck, obviously from the wire or harness he's using for that stunt.
Izzy is standing outside the church, gun in hand in a standoff with police. When Gabriel exits the church, Izzy quickly hands the gun to Gabriel, who is immediately met by a rain of police bullets. A number of exploding blood packets are clearly visible, almost extruding beneath Christopher Walken's shirt.