Other mistake: When Beast is flipping through his notes to try to determine what caused the explosion at the mansion a year earlier, you can see all the pages are blank. (00:13:50)
Other mistake: When Rogue is confronted by the Brotherhood after she absorbs Toad's powers, the Blob somehow walks up right behind her and only made two audible footsteps. The street Rogue was walking down was long, and Blob wasn't in view behind her a couple of shots before. Even if he emerged from an alley, he is so heavy that more than two of his footsteps would have been audible. (00:08:41)
Other mistake: When the Brotherhood steals Senator Kelly's Hummer, the Blob is sitting in the back. Blob is so heavy that he leaves holes in the ground when he walks, but the back end of the Hummer doesn't stoop closer to the ground when he's in it. (00:11:54)
Other mistake: When Magma is running from the MRD at the beginning, her feet are so hot that she leaves magma-filled footprints in the ground, but somehow her shoes remain intact. (00:01:54 - 00:02:34)
Other mistake: When Wolverine puts on his motorcycle helmet, the visor is down. When he pulls out of mansion grounds and stops to sniff Gambit's scent, the visor raises without him touching it. (00:08:27)