Did Castiel Go Too Far with Donatello on 'Supernatural'?

Desperate times call for desperate measures, or if you're Castiel on Supernatural, the potential of desperate times calls for desperate measures. In the episode "Good Intentions," worried about the chance that Michael from the Apocalypse World might destroy everything, Cas dove into the mind of a corrupted Donatello. The process destroyed Donatello's mind, leaving him brain-dead. It's a callous move but one that Cas deemed necessary. While he might be right, the moment doesn't suggest great things for the future of Supernatural's favorite angel.