Lewis' ice cream cone changes in between shots.
While Heather and Moondog hang out of the convenient store before they head off to rehab, Moondog pops in a cigar in his mouth - which disappears in the next shot.
During a dolphin tour, Captain Wack goes swimming with what he thinks are dolphins - but are actually sharks. The fins appear to be transparent as they're computer generated.
When Moondog punches the code to open the front gate, he presses the same button three times in a row, but the beeps change in pitch. They should have all been the same since they were supposedly generated by the same button.
When Moondog gazes at himself in a hospital mirror, the cameraman is partially visible in one section of the mirror.
As Moondog smooths things over with Heather and Frank while they cut their wedding cake, the camera's shadow vaguely passes behind Heather's back.
One slow-mo side shot of Moondog playing the piano reveals a camera rig's shadow on the ground.