Ain’t jelly, it’s jammed.
And your going to have a hard time hitting anything if that’s on auto.
It doesn’t look jammed - and he may have been mag swapping during lulls in the fight/when he got a chance, as you’re supposed to. Last mag being empty is probably the one that was in the gun when they got in close and he was forced to resort to the grenade.
“Ain’t jelly, it’s jammed.”
It’s called a tactical reload.
L