When left for dead in the Rocky Mountain wilderness, a fur trapper must call on all his will to survive to track down the man who murdered his son in front of him.

Nir Shelter:

Then what script?tag?applies to the bear mauling???It's an important, necessary plot beat. (Because as I?indicated earlier, if there is no mauling, then there is no murder, etc.)

In the grand scheme of screenwriting terminology, what would you call that event?? It clearly upsets the status quo, changes the life course of the protagonist.

The bear attack on it's own only motivated the protagonist to stay alive not seek revenge, however the attack enabled the inciting incident which was the killing of the son as a result of which the protagonist sought his goal of revenge.

The bear mauling is the inciting incident, the event that triggers the plot, sets off the chain reaction of events.??If there is no mauling, there's is no plot.? None of the other events follow as a consequence.