Well first off, they're probably going to pause and think of a way out if they don't abort the productions entirely and for good.
Thought one : They could, if they continue, make him disappear in two possible ways
a)Sudden disappearance and an antagonist (e.g. Ian Shaw) provoking it was them.
b)Faceover and visual death of Brian(stunt double, or anybody/-thing similar), which would be horrifying though...
Though at this time, I believe that the movie is far from relevant and the next most important thing would be the investigation...