I thinking having a player like TO does make a difference in those sack numbers.
First, in fairness to the Oline, I'd credit a 2-3 of those sacks Sunday to the coverage by the Broncos and/or the Cowboy's WR's inability to get open.
There were a few plays where Romo had good protection for a few seconds before it finally broke down. It's also Romo hanging on to the ball instead of maybe throwing it away. I'd say the sack/fumble was the blocking b/c Dumervil came untouched and it was just a good call by the defense.
<sarcasm> Of course if Owens is there, Romo's *forced* to throw to him so he gets rid of the ball, he isn't sacked. </sarcasm>
I don't recall seeing many double-teams on any of the Dallas WRs, which means teams are likely sending an extra guy. TO mades a difference IMO.