Red Superfly
You creepy little stalker
Would have been funny if Luke just chopped Vader right across and the movie ended right there haha.
I just like that scene, regardless of the flaw.
The bit where Luke nicks Vader tells us a lot about the situation: Vader let his guard down and Luke capitalises, only for Vader to get pissed right off and ends the game quickly.
I also thinkthe so-called "crappy" choreography in that scene makes it look more like a fight that is actually happening, rather than a special choregraphed dance (like the PTs fights). I'd rather have Luke do a dodgy sabre blow than watch him do some camp twirl and a backflip. The fight is raw, and it's part of its charm.
I like the idea Luke was already on the dodge before he cut any further into Vader. If Luke didn't swing back and defend, Vader would have hit him just as he'd kill Vader, meaning they'd both likely be dead.
It's also just a fight. The meaning and emotion of that fight, what that scene is ultimately telling us about the situation is ten times more important than the accuracy of the "physics" at play there, despite the fact lightsabers can cut anything apart from another saber or equivalent type of energy (Grievous' guard staffs).
Cortosis is also a load of bullshit.