"I can't lose you!" Ed tells his brother, voice heated with fear. "Not again!" But... dammit, Al's just as stubborn as Ed himself is... Al's made up his mind; he'll fight, even if it means he'll get hurt, or worse. Shaking, he squeezes his eyes shut again, retrieves a Zat from one of the fallen SFs, opens his eyes again, takes aim at the former SG team leader, and squeezes off a shot. The soldier collapses to the ground, jerking with spasms for a second or two before going still.

Even though they might not be able to get the parasite out of the USAF officer... which would mean he'd be stuck, screaming inside his own head, unable to control his own body for as long as the Goa'uld remained wrapped around his spinal cord... he can't bring himself to kill any of them. He can only fire stunning shots.