When Sam is reading about the demon killing spell Rowena used he says the name of the spell in Latin, then acts as if he is concentrating on translating it into English. However the English translation of the spell is right there on the webpage he was just reading.
When Dean fights with Cole, he throws Cole at a parked car and sends him through the windshield. Windshields are made of laminated glass which does not shatter like regular or tempered glass. It would crack into a spiderweb fracture but remain in one piece.