If a turn happens, it won't be during the match but after. There's no motivation for Orton to betray Bryan (or vice versa) while actively fighting for a chance to take the tag team championships away from The Shield. If one or the other causes them to lose the match, however, I could see tension leading to someone's beat down.
I think they'd be massively Blue to turn Bryan heel from all of this. For one, he's extremely popular and the fact that he's a newer face to WWE than Orton makes for a fresher baby face character on the roster in general. Why kill that kind of momentum? Secondly, he's rumored to face Cena next month and it might be silly for him to turn heel and go straight into a world title feud without having a full fledged feud with his former partner Kane or even Orton first (unless he won the title and had a feud over the belt with those two, but I'm not gullible enough to believe that we have a Cena-less main event with Bryan headlining against Orton or Kane, especially for Summerslam.)
If anyone turns at all (I'm not 100% convinced they are), it should obviously be Orton. Even though he's a pretty over face, too. Bryan surviving a punt kick and coming back after Orton plays into his "Fighter who just won't quit" persona quite well.
