Uh the girl entered on her own that's why he said "you can't just come in without permission!" while blocking her way before he got shot.
Dude he didn't let her in??? She barged in while he was telling chase a fellow actress ON SET wants to meet him. She's not some unknown stranger, so there was no need to tie her up until he gets Chase's response first. He went in, asked, and she overheard his response from the outside so she pushed herself in. She engaged with Chase in a back and forth argument so the bodyguard wouldn't cut them off but he'd hold her back until Chase said get her out of here, which he promptly tried to do until she pulled out a gun. At that point, Chase's safety was more important than keeping her out because she could shoot any moment.
What's so hard to understand?
Maybe the bodyguard should've been more careful, but he had no reason to suspect one of the main actresses in a movie they've been filming for months and on set with her for that time without any incident or hostility or reason for suspicion.
Also Becky is an actress(might also be an important figure as she was invited by pittman tho it was never explained in the novel) as well so a bodyguard can't exactly push her by physically touching her all he can do is block her and tell her to go out
Omg is it his first day at work or smth?
It’s his job to suspect everyone
What’s wrong with the bodyguard? Why would he let someone in when Chase didn’t approve, like do you even know your freaking job description? It doesn’t matter if it doesn’t make sense to you, you do what you are told to protect the person who you should protect