I've seen that happen to a lot of people over the years, and she did better than most when faced with a sudden sharp pain from a hot casing. She kept the muzzle downrange, didn't completely freak out/scream, and put the weapon down on the bench before addressing the problem.
Two thumbs up!
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)
when i shot my old usaf issue m16 left handed it ejected hot shells at my shoulder which then bounced down to my bent support arm. one out of three would find a spot under the rolled up sleeve against the flesh in the crook of my arm or in the neck area. i hated unrolling the sleeves and i nearly cried with joy when we got the mp5's.