And Glo last but not least, no matter what is your shipping perspective. Dan IS the best person for Blair as of right now. that is the very point of their love story at least for Blair : No one has ever treated her as respectfully and as selflessly as he does. With her, he is the most selfless (CB reunion, no confession of his feelings), the most concerned with her happiness (telling her not to marry Louis, CB reunion), the most supportive (when she sees C with his "sacred" Raina), the one who forces her to be honest (paternity test)... It's not a coincidence she's been running back to him all the time in S5, if you view it as one and don't think C and S deserve what is happening to them right now, you will be surprised by a lot of stuff I suppose.
And what does it matter really? CBers still love CB despite all the things C has done that were the worst things ever on this show. Surely, Dan being right or wrong (imo right tbh. I really hope he did) sending that video isn't supposed to turn us off?
I have no intention of turning anyone off or changing anyone's mind, it's purely my view. The writing leaves LOTS of room for interpretation and plenty of unanswered questions. It's kinda frustrating to keep up and I should stop thinking too hard about this show. I'm working on that...
And Blair saying 'How could Serena not love you?' was a tv trope used to launch the DB storyline. Blair needed to realize that Dan is a pretty awesome guy that any girl would be lucky to have so that she can develop feelings for him. I don't think she puts him on a pedastal. She gets more mad at him when he screws up then with others so she actually judges him more harshly.
I just pointed that out because if SB were actually communicating. Blair would know that Dan is the complete opposite to Serena.