Morimoto's guards are really bad at their job. They (really half-heartedly) scan people with the handheld metal detector. They detect Gwen's altered invitation and tell her to "Step this way" (without saying which way) and then just stand there as she and Gunn have a private conference. When Gunn starts up a conversation with Morimoto they still don't do anything. Finally Gunn gives Morimoto the gift and the guards then, finally, decide to try and get them to do something.