Rufus is a naked mole rat, a real-life completely hairless animal (as explained repeatedly throughout this series), but when he gets electrocuted he has frizzed fur.
When Kim and Ron take the elevator down to Drakken's lair, Ron is wearing gloves. Yet when he snaps his fingers in time to the Muzak, we hear him as if he were not wearing gloves.
The brain-switch subjects also switch vocal cords, a fact which Shego and other characters notice and comment on. Within the story parameters that we're given, this makes no sense.