Through the entire fight scene in the lobby with Mr. Craig Jason had to have his mind on Elizabeth and where she was located. The police shot in tear-gas, guns were going off, no one was sure where to run or where to hide.But jason found Liz and scooped her up to safety. Robin needed assistance, there was no guarantee that Nik was going to save Emily (and come to think of it he didn't)Maxi didn't have anyone looking out for her. And if Sam hadn't gotten out through the second floor and still been in the lobby, who do you think Jason would have saved? Elizabeth still?
I definitely think he would have chosen Liz, but if he had tried to save Sam over Liz, Sam would have told him to help Liz. Sam was so compassionate (I know, I can't believe I am saying this) towards Liz during the hostage situation that she would have told Jason to save Liz and the baby. But I still think he would have saved Liz first.
There is no if about it! He clearly choose Sam; that is why he made sure she got out before there was any chance of her getting caught in the explosion. However if it had turned out that both of them were still in the building when the explosion had happened Jason would have made sure Sam was right next to him, then with her instance and her help he would have made every effort to save Liz too. That is just the kind of people Jason and Sam are!
I believe he would have tried to save Liz, because she's pregnant regardless at the time he didn't know the baby was his, Sam was capable of getting herself out...She USED to be so strong why would she need Jason to save her.
Sam does not NEED Jason to save her (like Liz does) Sam can save herself, however the question was Who would Jason have choosen? Like I said before IF Jason had not already made sure Sam was safe, he would have made sure she was with him when the explosion happen and with SAM's help THEY would have saved Liz because she obviously couldn't save herself!