miss me?

Yes, it's true that he hugged her at the airport when saying goodbye, but then again he did think he was going to die. He thought that was the last time he'd ever see John, which was probably why he wanted to make it as undramatic as possible. I think he considered everything. Mary was not done with her assassin job, at least not completely, and I think Sherlock must've done something to ensure John's safety. Perhaps he talked to Mycroft, asked him to keep an eye on his best friend, considering he would never see him again.

Sherlock's not stupid or naïve, and I think he lost all the trust he had for Mary the moment she shot him. I know he was a bit slow with her- not figuring out who she really was or what her past was like (the only negative thing that could potentially give her away was that she was a liar), but I think it has to do with the fact that she was the first (and possibly the only) John's girlfriend he genuinely liked. She was snarky, observant and most important of all she didn't hate him. And yet, I am fairly sure he lost all the respect he had for her in the moment she shot him.