Good question. I don't know if they would have beaten Dallas, but I do think they would've played better. After his return in Game 4, Dallas guards really exposed his lack of later movement on D, and made him a lot less effective on D. He didn't have his legs, so all his 3's were coming up short.
Dallas is a tough team. They are so deep, and I think it was our lack of depth that killed us moreso than Raja being hurt. They were running on fumes.