You accept the possibility that you will be killed in action, but not that you will be simply murdered.
And unlike Malmedy it wasn't a case of slaughtering prisoners
It actually depends on the motivation. If Forrest shot those men only because they were trying to escape, then Fort Pillow wasn't like Malmedy.
But if Forrest shot them because they had earlier refused to surrender, or because they were Negro troops, then yep, it was a Malmedy.
I suppose it boils down to this: did Forrest order the shooting of the men who had surrendered and weren't trying to escape? To this day, that question is being debated.
Trying to escape to fight another day is an action.
If they weren’t prisoners, then nope, it wasn’t a Malmedy.
If Forrest ordered the shooting the men who had surrendered then of course that changes everything.