In the scene where Luke reunites with Biggs and meets Red Leader, when Lucas added the scene back in, he deleted one of Red Leader’s lines, which went something like:

“I met your father when I was just a boy. He was a great pilot. If you’re half as good as he was, you’ll do alright.”

Apparently, the line was cut because Lucas thought it contradicted the lore that he’d established later. But does it, really, though? Couldn’t Anakin have met Red Leader during the Clone Wars?