Yeah, I thought I noticed that too, so I went back and checked. When we first see him, he's standing up and has the badge on his uniform, but then when the camera changes and he sits down in his chair, it's gone. After that, I think he has it back on for the rest of the scene, but I'd have to rewatch the whole thing to be sure.
There is another mistake... a real one... when kirk leaves spock... he goes through a tunnel... he has a ROMULAN DISRUPTOR AT HAND, when he leaves the tunnel, he has a phaser in hand and it is taken away from him!
I love the chart! You know, I've seen the film 3 times now, and will be going for a fourth, but still can't figure out the turbolift! That's about as close as it will get, with that diagram!
And...of course...being Robau, he couldn't take the quickest and most direct route...because that would have been showing weakness.
Robau took the damned route he wanted. stopped off for a shave and a quick drink. Nero can just effing wait.
This would make sense, since the Turbolift would need to bypass the Impulse engine assembly, as well as the power and intermix interfaces with the nacelle below. That Impulse deck, and those connecting pylons to Engineering and the Warp Nacelle must be pretty packed !!!
^ Or it could just be that Robau took the long way around to have enough time to sex/badass himself up.