I amnot a green screen expert. Reading the other comments, I wanted to add this: you can have a fake background with things moving, like trees, right? And, we never see him actually get on the helicopter. To me, the whole quality of it is strange... he is crystal clear and 3-dimensional, whereas everything else looks so 2-dimensional. It's like if you're in a movie theater and someone walks across the stage with the movie playing behind them (although nevermind the shadow in my example).

I don't know if it's fake... but it looks like shit.