This, pretty much. If Dez catches it, Dallas probably takes a 27-26 or 29-26 lead. And what? League MVP A-Rod will simply march the Packers downfield for the winning score.
This reminds me of people who blame Romo's bobbled snap for the Cowboys losing to Seattle, forgetting that it would have been merely a 23-21 Dallas lead had the snap gone cleanly. What happens next? We all know what comes next; Hasselbeck exploiting the weak coverage of strong safety Roy Williams. Seattle would have marched downfield, kicked a field goal of their own and won 24-23.