Early on, when David Banner sneaks into Dr. Pratt's lab, he erases a letter from work board showing the scientific equation of DNA structure and substitutes the letter "A" for what he has erased. At various times during the movie, when the board is shown again, the letter "A" is in different handwriting (one must look closely to see). Sometimes the top of the letter is rounded off, sometimes it comes to a sharp point. Sometimes the two "legs" of the letter "A" are equal, sometimes the right "leg" is longer than the left "leg".
Near the end of the movie, when the Hulk falls from the exploding airplane, he is first shown (from a distance) in front of the flames, falling face down. Immediately thereafter he shown falling face up, then again falling face down, then finally again, falling face up. At no time is there any indication that he is spinning or tumbling. Also, when the camera zooms in on his shoulder, part of the table Lou Ferrigno is lying on is visible.
When Jasmin is cutting the window to break into the airport (near the end of the movie), she is cutting at the bottom of the window pane, with the lower cut being only an inch or so from the pane bottom. Immediately thereafter, when she is shown removing the freshly cut piece of glass, the section cut is now from the middle of the pane, about four to six inches higher than shown seconds before.
After the failed experiment, when The Hulk is escaping the lab, he rips open a chain link fence, but as it's shown in slow motion, you can plainly see that none of the links are ripped or broken or torn, so it was really just two overlapping fences that he separates.