During the part where the green goblin is testing his formula, after the other doctor straps him in and lifts the table up, he has electrodes on his chest, but they weren't there before. Goblin couldn't have put them on himself, as he was strapped to the table. So who put them on???
I saw this one too when I watched the movie in the theater. It's defenitely a slip up. Can't believe the makers of the film haven't seen it! It was so obvious.
If you watch after Osbourns Assistint straps him in there is about five seconds where you only see the assistants face. My guess is that would be there explanation. Because if you look at the table before hand the electrodes are laying to the right of Osbourns head.