Good catch--its a digital foreground cross to hide a time-cut. Original Rebel pilot remembers Luke's father as a great pilot that he knew as a boy. Thats why Rebel leader's attitude changes rather abruptly. The original scene scene had Biggs say "Sir, Luke is the best bush pilot in the outer rim territories," to which Rebel Leader says "Skywalker? I knew your father when I was a boy. He was a great pilot. If your half the man he was you'll do okay." The middle part was cut out and hidden with a digital foreground cross of an extra.