Large breed dog wont jump.

I spent time with a large breed dog (2yo) in hopes of making a match. I came away with a few concerns, but the biggist was that he did not want to jump up onto anything or into a car. AT ALL., even with high value treats (he is BIG on treats). I was told he was texture sensitive, but he had no problem putting his pwa up on what ever it was, just wouldn't jump. He had to be lifted. Didn't spend a long time with the dog (24h) But was told that the dogs reluctance would go away after the transition period. How likley is that? I want to call BS, but I am not sure.