It says pending approval still so it could change. I could see the gun being added to his hand as an accessory.
These are the two best images from that scene in the film show just what was going on. There are issues with it, but I forgive some things as it was a very quick scene and to make work as a piece like this it needed edits. Especially with the raptor, just look at the neck on the film one, what we see in film is usually very different than what appears behind the scenes.
Yes Muldoon's hat should not be on his head, make it removable if it's an issue, simple fix. Add the gun back. The socks are pretty thick looking.
I've seen a lot of people saying this is the "Big One" and from what I've always understood it's not. The Big One is who Muldoon thought he was setting up to shoot then one of her pack attacks him. She outsmarted him so "Clever Girl ".