Yup, my wingman does it all the time. It's not so bad now when the enemy is armed. I let them have the first go. They swoop down shoot each other up and limp back home. That's when I step in an sweep whatever's left over. Usually by then the rear gunner is knocked out and the plane on its last leg.
It was a totally different story with BI's - pretty much a "race" to get there first and try to shoot the poor #%&*$# down before the rest gets its turn.

"Take the cylinder out of my kidneys,
The connecting rod out of my brain, my brain,
From out of my arse take the camshaft,
And assemble the engine again."