Normally on reality shows, production is doing a good deal of plotting and cajoling to get the most explosive scenes possible and to plant seeds of distrust within the cast.
But there is production, and there is production. Each reality show has a network production team that overseas the production team that actually is responsible for carrying out the day to day filming schedules. The network folks have the ultimate control but generally let the boots on the ground make the decisions about day to day filming and how the storyarcs that the network wants to see come to fruition. For the most part, the network suits come into play more in post production when certain storyarcs are feature and others may be completely obliterated. Sometimes even obliterating a particular castmate all together.
But recently, the network producers completely blindside the production company for hire on location. Absolutely no one knew that a former castmate was going to make an appearance. Including the show runner. And the show runner only found out hours before filming.
That is because the show runner and the former castmate have vowed not to work together The show runner, was irate. There were many hostile conversations between the show runner and the network suits. The show runner wanted to leave (again) and stop working with the network. However, the local production company also has another show in the works with that network. They are also working on a show with a competitive network that the owners of the first network may be about to purchase. So everyone has to play nice.
The result is that a show that both the network and the production company have in common was finally given the green light at a very strange time. The show in question was not expected to push for several months but it is now receiving a lot of attention.
My sources say this is all related to the incident with the former castmate showing up to a filming scene unexpectedly. The new show moving to the forefront is the result of a peace treaty between one boots on the ground production company and the NYC suits. So one little filming stunt has worked out very well for the disgruntled show runner who know has back to back seasons on the network.