During Castiel's speech to Dean, he loses his trademark rumble. This is because the rumble is an affectation by actor Misha Collins, and accents and voice changes are hard to maintain during states of high emotion.
When Sam is texting Eileen, the letters he presses are not the ones showing up in the conversation. Also, the keyboard always displays upper case letters and no question mark, even though he uses both lower case and the question mark.