In Star Wars (A New Hope, if you must), there's a scene when Vader is talking to Grand Moff Tarkin.
Vader's voice stops, and then a second later Vader raises his hand and wags his finger at Tarkin.
Tarkin: "She lied. She lied to us."
Vader: "I told you she would never consciously betray the rebellion."
Vader awkwardly wags his finger at Tarkin after already having finished his line.
It's well known that Vader's voice was added later, performed by James Earl Jones.
Q1. But why didn't George Lucas cut this moment before the finger wag? Why leave the awkward silence? (Or add some cuts so the finger was raised at the right moment.)
Q2. I can only assume there was additional dialog there that got cut. Is there anything that tells what what was was said originally?