What happened in the pits was an incident, thankful that nobody got hurt. Could have been avoided but it wasn't intentional.
What happened with Schumacher was a deliberate act. He chose to force Ruebens over, he should have chosen to defend the position before Ruebens was by his side. But also he had more time to decide to do this than say Webber hitting the Lotus for example. Its clear to see he knew he was there, and what he was doing, its inexcusable. He made that decision, and its one that could have been fatal, get him out of the car, chop his arms and legs off and spear him onto a 200ft flag pole.