A key witness in the Navy SEAL court-martial trial said he, not Chief Edward Gallagher, killed a wounded Isis fighter in Iraq in 2017, testimony which appears to up-end the prosecution’s main claim in a nationally-watched murder and attempted murder case. Corey Scott, a first class petty officer, testified that he was there and saw Gallagher stab the wounded ISIS fighter in the neck but, he said, he killed the fighter afterward. Scott said he used his thumb to cover the breathing tube that had been inserted to help the fighter breathe and he watched the man die. He said he did it to spare the fighter from being tortured later by members of the Iraqi Emergency Response Division, who also were fighting ISIS.