The scope of material I can work with is not limited to the set of things that we inherit from nature.
Facetiousness is allowable when it is the most proper instrument of exposing things apparently base and vile to due contempt.
An actor would be foolish to do something that might hold up the picture, or more importantly incapacitate him. If an actor does do a stunt he needs to make sure a stunt man stands by to see that it's done correctly.