I wonder why they said this would confuse people. Is that because someone lied about Pelosi opening the door? Otherwise, I think it sheds much light on the event.
I watched the beginning of the video several times. Who opened the door? Pelosi has his right hand on the hammer as soon as he comes into view as the door is opening. DePape also has his right hand on the hammer as he comes into view. Pelosi's left had is holding his drink, which shows as they move around, and DePape's left hand/arm is blocked by Pelosi's. DePape is trying to bring his left hand around and use both of his hands to get the hammer from Pelosi. Was there a third person off camera behind the door? Neither Pelosi or DePape appear close enough to it to have opened the door and there wasn't enough time for Pelosi to open the door and grab the hammer or his drink before he's seen in frame.