Continuity mistake: During Cain's escape attempt RoboCop seizes someone's motorcycle. The motorcycle's lights vary between being on or off throughout the scene.
Continuity mistake: While Lewis is shooting the baseball coach, she makes two holes on the glass of the van but they disappear when Robo is holding the dead body.
Continuity mistake: When the girl is spraying graffiti on Robocop, the last mark on his head is a light dot. Yet a moment later when shooting at the smoker, it's a bright orange line.
Continuity mistake: When "Robocop 2" goes beserk, he shoots several civilians and a row of OCP security. The last civilian to be hit in that scene is later seen being helped down a flight of stairs by two folks as the President of OCP talks with some of his subordinates about who to lay blame on for the incident.
Answer: Just so it would look creepy in the jar (or maybe they thought they were worth keeping, then decided against it). Notice when Robocop pulls Kane's brain out of the 'bot later, the eyes are no longer there.
Grumpy Scot