Deliberate mistake: Bowser has several teeth that appear and disappear throughout the movie. The best example of this is when Mario is trying to grab the Power Star. We see Bowser snarl at Mario before he picks him up. There is a gap between his two front teeth. However, when the scene cuts from Mario's horrified face to Bowser's face, there are now extra teeth inside that gap.
Deliberate mistake: While the events depicted in the film take place over nearly a decade and a half, the characters are not shown as having aged at all throughout the film, apart from Mike Lazaridis. In fact, characters are seen wearing the same clothes and the same ties between scenes that are set years apart.
Deliberate mistake: Kristin would not be physically able to hold Fabrizio from falling over the ledge using only one hand/arm (or even both). (01:30:22)