Near the end, Sarah triggers an explosion by hitting the previously placed explosives with an arrow. The explosion is shown in 2 successive shots. In the 2nd shot, one of the O'Hara brothers behaves like he was standing near the explosion and got gravely injured. However, it is blatantly obvious that there was nobody near the explosion in the 1st shot, which means that O'Hara abruptly appeared there between the shots.
At around 23 minutes, Burt fires his revolver several times. Just a few seconds later, Ramon nonchalantly grabs the barrel of Burt's revolver. This would be impossible in reality, as the recent discharges of the revolver would make its barrel too hot to touch.