Buddy of mine was on Judge Judy as a witness.

He said he never interacted with Judy except when recording - they literally never spoke when the cameras weren't rolling. The "trial" (actually an arbitration session) was interrupted pretty regularly as producers asked both Judy and the participants to repeat or rephrase certain things with different emotions. That said, they never messed with the content of the arguments, just their delivery, and overall my buddy thought the actual decision process was more or less fair.

That said, one funny thing is the plaintiff and defendent were actually friends - Judge Judy pays both the plaintiff and the defendant, win or lose. They easily could've solved the issue themselves, it wasn't like they were at each other's throats, they just thought it would be fun to be on TV and make a few bucks besides.