Other mistake: About halfway through the film, there is a screw-up in the editing. After Serleena talks to the thugs, she proceeds to talk to Jarra. The next time we see her, she is interrogating Zed. Soon after, she is talking to Jarra as if she was never interrupted. (00:39:25 - 01:03:40)
Other mistake: In the opening scene when Sarleena takes the Vic Secret model's appearance the tentacles are just completing her face when the guy grabs her. He had to have seen the tentacles "building" her as he was walking up to her. (00:05:50)
Other mistake: When Jay opens the post office sorting machine and we see the multi-armed alien, there is a stereo playing rock music quite loudly. There's also a hole on the other side of the machine (to fire the letters out of) - shouldn't we have been able to hear the music through that hole before Jay opened the machine? (00:28:10)
Other mistake: When Agent J. is riding the Giant Worm in the subway, you see him getting hit by a metal bar on the top of the tunnel smack right in the head at amazing speed, twice! Yes, twice that happened. And later, when he is sitting on the bench with his partner, you see his head looks completely untouched, no cuts, blood, scars, absolutely nothing. Certainly he would at least have a little mark, but nope, nothing but a little sweat. Does Agent J. have a hard head or what? (00:08:05)
Answer: They are extraterrestrials, the fact they are weird gives it away to K now he has been deneuralized. He started to notice them again as his mind is rebooting.
lionhead