Different angle for the pick.
Couple of thoughts from my perspective. First, it seems Escobar was Romo's 2nd or 3rd read, and Murray was probably his last read in his progression. It seemed like Escobar was getting open, and Romo made the decision to throw it to him. Romo said in the press conference he wanted to get the ball 1 or 2 feet ahead of Escobar, but the circumstances in the pocket did not allow him to throw the ball the way he wanted.
Second, Romo's front foot does get caught on the leg of his left tackle (Tyron Smith), which leads him to become a little off balanced.
Third, the left guard (Ronal Leary), in trying to help his Center, blocks off space for Romo to step into the throw, which I think also altered the velocity of the throw.
http://www.bloggingtheboys.com/2013...ciphering-the-decision-tony-romo-interception
This link goes into a little bit more detail about Romo's decision and the circumstances of the play.