Professor Pembroke was thrown off the stairs because he teaches muggle studies and is muggleborn. It was a political move to force the new Minister make a statement regarding his feelings on muggleborns because he's usually so wishy-washy about his views unless forced.
Professor Pembroke caught Professor Prince and Miss Binns together in a compromising position so they planned to kill him to keep him from talking. That's why Professor Prince was one of the first Professors on the scene of the incident.
Ignatius Prince @"Emma Binns"Coach Crouch is a sketchy guy. He probably threw Professor Pembroke off the stairs so he could sub for his class. Being a Professor gets more respect than being a flying instructor, after all. He might even switch to do it permanently!
The following 3 users Like Rumour Mill's post:
Amarantha Valenduris, Ignatius Prince, Jessamine Parkinson
Amarantha Valenduris, Ignatius Prince, Jessamine Parkinson