Continuity mistake: The Bug pulls his new "Edgar Suit" skin back tight over his face and the wife faints. In the wide shot, he is still holding it back, but the head is completely normal. (00:15:30)
Continuity mistake: Before Kay erases the memories of the border patrol cops, he holds the neuralizer with his left hand while adjusting its knobs with his right hand. In the next shot, he's holding the neuralizer with his right hand.
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