Here's a personal anecdote about the random falling object / Luke's hand / broken vane piece:

I was watching ESB with my 7 year-old son a few weeks ago. When the whatever-it-was fell down, my son was very confused. He asked what fell, and I didn't have a good answer for him. I told him it was Luke's jacket. I know it wasn't, but it always seemed to look like an empty jacket falling.

Granted, confusing a 7 year-old is not that hard, but this is a good example of how the unknown object somewhat ruins the impact of the scene. Half your brain is thinking "whoa, that's a long drop", and the other half of your brain is thinking "wtf was THAT?"

Some kind of brief shot of Luke knocking part of the vane off (with his hand, butt, etc.) would go a long way to fixing this.

My humble 2 cents.