Revenge...um...I mean...Return of the Jedi
Not many goofs...but they're there.

Balancing Off the Tip and...Pink Blade?
Yeah, you hear a little sound effect of the tip of the blade touching the step but the effect would have been more complete with a little spark.
Also, what's up with the pink blade? On and off it switches from Red to Pink. Was he using "Pink-5's" lightsaber by mistake?

Since When Does Light Itself Cast a Shadow?
Never as far as I knew. I guess this wasn't important enough to "digitally erase" from the floor.

The Butt of a Joke
I guess they never counted on a frame by frame analysis when they completed this shot which clearly shows the blade coming out of the wrong end (the butt end) of the lightsaber hilt.

Hey Vader, Why You Got That (Luke) Lightsaber in Your Hand?
This is probably the most missed goof of all. The scene was originally cut with Luke throwing his lightsaber out to Vader, declaring his unwillingness to fight and Vader picks it up. Because the scene was re-cut the shot of Vader holding Luke's lightsaber can still be seen in his hand. Again, one of those things they never counted on anyone catching...but we did.

You Didn't Need Those Eyebrows, Did You Mr. Hammill?
Either Mark, missed his mark or the pyrotechnics missed theirs. Either way, this had to be unpleasant.

Pesky Shadows Hogging the Spotlight Again!
Who knows. Maybe someday they'll fix it.

Well Give The Guy a Hand...or...Take One
Not a clean setup but I guess it got the job done.

Choppy Blade Effects
I guess they wanted it to look like the smoke was obscuring the blade glow. However I found this to be unnecessary. Smoke isn't that dense.

Is it Over or Under?
It's probably supposed to be under the rail, I think this was just a little sloppy.