Did Vader let Luke win (I know it's an old question, but there's a specific detail that makes me think so)

When Luke and Vader fight and Luke is enraged, look closely at what happens.They enter the bridge. Vader evades (lol) Luke's slashes, BUT, for really no reason at all, goes to his knees and leans on the ceiling, basically just letting Luke slash his hand off.There is literally no visible reason for Vader to go to his knees there. There was enough space on the bridge to keep going backwards.It doesn't look like a big deal when you're captured by the movie and the emotions, but if you look at that scene objectively and maybe without the soundtrack, it looks rather obvious. There wasn't anything Luke did to force Vader to his knees. via /r/StarWars http://ift.tt/2wfo1KG