Continuity mistake: When Max and Freak go into the coffee shop, Max says hello to Mr. Hampton and puts three Baby Ruth chocolate bars down on the counter in closeup. Then it changes to a longer shot and Max puts the chocolate bars down again.
Continuity mistake: When the cops capture Killer Kane, the first cop to grab him loses his hat in the struggle. In the very next shot of him, just before the other cops arrive, he has his hat on again. While there might have been just enough time for him to put the hat on while the camera was not on him, he would have had to do so before handcuffing his prisoner - probably not a good idea.
Factual error: When Max received a letter, the address showed that he lived in Cincinnati. But at the end of the movie, Max winds up Freak's bird, and lets it fly over the river towards the Cincinnati skyline. This means he is on the other side of the river, in Newport Kentucky.
Continuity mistake: When Kevin sleds down the hill, he flies through the air when he reaches the dead end and he crashes face first into a pile of snow. By the way he falls it seems he only fell a few feet because he did not hit the ground hard. But in reality, he was falling about ten feet.
Continuity mistake: When Max takes the garbage out and sees Freak over the fence for the first time, the first camera angle (looking straight down from above) shows that he is not wearing his headphones. However, the very next shot (looking at Max from the front) shows him removing his headphones. And yes, they are the kind with the shiny metal band that goes over the top of his head, so they should have been visible in both shots.