Most reality shows liberally mix the live stuff with re-enacted bits. The trouble is that there's a fine line between re-enactment and outright lying. Operation Repo peed all over that line when they filmed an episode in which one of their repo crews got chased by a shotgun-wielding psychopath ...
... only to have an eagle-eyed viewer spot that this apparently unhinged gun nut's property was actually just a set, also used for an episode of Jackass:
No death threats, even though this time it'd be absolutely deserved.
We also leave a lot of gold on the cutting room floor whenever it's at odds with how our producers want someone's "character" to develop. We had one cast member spend two straight nights in a vet's office, waiting to see if his dog was going to live through a terrible illness. That's gripping, personal stuff. But the show had built him up as this cold, emotionless person, so we couldn't show him crying after that. We wound up cutting that whole bit because it humanized a human too much.
"The director wants you to call him a bad dog and show him clips of Old Yeller."