
Continuity mistake: Just before the diner scene, where the two aliens are discussing the galaxy, we see the outside of the Russian restaurant. The neon sign says "haroshaya" meaning "good" all the way across the window, in the next shot inside the restaurant, the "ha", which looks like the English letters "xo", is gone and the sign is centered. (00:41:00)
Answer: David Cross plays Newton in both movies. In the first he is attacked by the Bug but survives and something went wrong with his neuralyzing as in the sequel he knows small things about the men in black like how they appear and he recognises the neuralyzer from his previous encounter with it, which isn't a coincidence. It appears J's neuralyzing of Newton did work and we don't see him in the 3rd movie (probably because he is in jail for the murder of his mother).
lionhead