How does "hold_R_handgun" work?

I've been wondering if there's an easier way to recreate the hold_R_handgun animation. This animation, when triggered, appears to have two states. When out of mouselook, the avatar holds the object with the upper arm down and the lower arm forward, and in mouselook both arms extend forward and do an aiming pose.

Some sample code to see this:

default {
 	state_entry() {
 		llRequestPermissions(llGetOwner(), PERMISSION_TRIGGER_ANIMATION);   
 	}
 	run_time_permissions(integer permissions) {
 		llStartAnimation("hold_R_handgun");
 	}
 	touch_start(integer a) {
 		llStopAnimation("hold_R_handgun");
 	}
 }

This could easily be done by polling the avatar to see if it's in mouselook, however if it can be recreated through animations it would save on some lag/script space.

Unfortunately that animation is special and pretty much the only way I can think of replicating it is how you described, polling the avatar for mouselook and then playing a second animation when it's found