Tron Legacy, at least to me, was an example of a film that was let down by poor editing, especially during the fight scenes.

This movie was a lot of fun!

King Arthur: Legend of the Sword (31% @ RT)

This video appears to be missing an important step - keeping pressure on the flipper part of the blade so it doesn’t accidentally come down on your thumb as you disengage the lock. It helps if there is a more significant flipper guard on the knife, which the sample in the video appears to lack.