User blog comment:Dominic1743/“The Trap” Discussion/@comment-108.36.76.116-20200117052642/@comment-108.36.76.116-20200118133212

Yes, Dean trusted Sam back in season five, but not until after a lot of arguing. I think  this time, Dean was suprised, (as was Castiel) by what Sam did,but Dean  didn't jump from surprise to anger and fighting with Sam about it. After what he said to Castiel, it sounds like he's facing his anger issues. He wanted to know why, listened, and decided support Sam.