Unarmed close assault?

[iCaMpWiThAWP]

I recently was playing a battle, february 1991, USA assaults Iraq, after some turns, a platoon of abrams ran on my reserve company on my rear area, most of the squads were equipped with AKs, grenades, my heavy weapons got supressed by small arms fire, and i had to assault the M1 platoon since no rpg there, using my pinned infantry to button the tanks, one squado threw a grenade, non-penetrating hit, but mobility kill, by no pen grenade!, then i finished him off, gone for the second tank, assaulted him, with no weapon(it was written: Rifle Squad Assaulting M1... BUT no weapon was selected by the squad) and DESTROYED it, so how could they do this? Did they hopped over the tank, opened the turret and killed the man in there? is this a "bug"?