Ahh yes! There were times when I stared at the scene layouts and thought - now, making it even remotely canon-compliant is going to be a headache. Then I grinned at the dialogue and thought - canon or not, this was extremely fun to write anyway.
Dumbledore's phoenix tear sherbet was a last minute idea that sort of resonated in my mind with Harry's 'I'm about to die' snitch. As for the curtain, I think we both contributed to that - I suggested the idea of Harry wearing a curtain for a cape and Sinick filled in its appearance, role, and where it originated.