The person on twitter who said she saw Jared picking cherry blossoms out of Jensen’s hair also said she saw a hug between Dean and Cas. Keep in mind that she does ship D/C so there could be some exaggeration going on but I’m assuming she must have seen something like that.
Um. I have certain theories here that make me not very upset about this but I don’t really want to talk about them publicly because I could be totally wrong. Let me just say that I don’t think you need to worry yourself too much about it. Even if I am wrong, I don’t think it’s a big deal. Sam and Dean have both hugged Cas a couple times before.