Continuity mistake: When Principal Kelly is placing the caution tape across the destroyed restroom wall, he applies it at a diagonal angle. When the shot changes, the tape is now at a horizontal angle, and he is now applying a second piece at a diagonal angle.
Continuity mistake: After Rogue absorbs Blob's powers to stop him from collapsing the bleachers, the shot changes, and we see Blob falling to his knees, and Rogue standing directly behind him. The shot changes again, and Rogue is suddenly crouched down on the rubble with Kitty standing behind her, and Blob nowhere to be seen.
