Dez not catching the ball automatically gave the ball to Green Bay. Same result: turnover.
The 2007 loss to the Giants ending in an interception thrown by Romo could have ended with a win had Romo thrown a completion either in the endzone or in the red zone to give the offense one last try to score and win the game, so yes, Romo's interception at the end did contribute to the playoff game loss.
In the 2009 playoff loss, Romo's turnovers greatly contributed to the loss AND the 30 point difference. Who are you trying to kid trying to deflect responsibility? You don't do it for Dak, but suddenly, you want to do it for Romo? Get out of here with that...