I'd say losing both your legs in a hyper fast shower of molten tungsten is enough to make anyone stop shooting.
Also, I didn't say everyone is a bad shot, I said they were inexperienced. Everyone is trained and qualified to shoot a gun and wear PA, however, if his move were to fail and the other guys opened fire Richard is now standing dead center in the middle of a firefight. If he's going to gamble his life by trusting fully in a computer he's nuts. The computer cannot provide 100% accurate shots, especially when the weapon is bouncing around from the recoil of fully automatic gunfire. If the system was perfect no one would use armor, the PAs would be phased out by drones who can think/react faster, shoot straighter, and in every way out perform a human operator. The targeting computer is a tool that must be skillfully handled by the person using it. A bunch of weary marines may very well make a mistake, human error, and when that happens the consequences can be severe for the person who purposely places himself between the target and a row of shooters. Also, this Neko is probably not an idiot. Imagine:
A spray of death paints the wall next to her and she is yelled at but the shooter stops approaching. Another person tells her to drop the weapon and stops approaching.
At this point she's fully aware that her next move will be her last but has the option to surrender. Now continue:
Another person runs two strides past everyone else.
Here she can probably assume that he is not going to honor the request to surrender that the others have offered and is proceeding with the intent to bring her harm. She has an armor piercing weapon and a will to live, so what will she do? What would you do?
I wouldn't know what he intended to do, I'd be scared and panic and do exactly what I was trained to do. I'd shoot him right I'm the face.
Yeah sure the helmets are armored but I'll tell ya what, getting hit hard in the face by anything moving fast while wearing anything on your head hurts like a mother. Now I'm not the GM but my prediction is as follows:
He gets shot in the face and the monoeye get busted, so he's blind, and the shock of impact rattles his brain, so he falls over. Delmar, Ylfa, and Mark simultaneously open fire and shred the Neko, because machine guns and shotguns are messy, meaning we have no one to interrogate and a marine who needs medevac, because the kinetic force of impact can cause whiplash and disorientation made worse by the current state of blindness. All in all the result in my mind would be unfavorable. I'm not trying to be a jerk about things, I'm just letting you know he's in a horrible place as far as safety is concerned.
Additionally, we are in an RP where giant crabs fly and do barrel rolls... I wouldn't put it past a Neko to just walk through the force push thing and kick him straight in the nuts.