I don't think J&D are acting as villains. They stirred the pot this leg but they haven't resorted to any kind of manipulation like, say Rob & Amber. What I've noticed in most seasons is that once a team gets a close call, they put their game faces on and start racing seriously, and make sure they don't make any mistakes. The most obvious example is Tammy & Victor after their breakdown in Romania. They had a close call but became aware of their disadvantages and were able to overcome them for the rest of their race.
This season, Justin & Diana already had their close call in episode 1. If you pay attention, they only get cocky once they're on the mat, so I'm pretty sure the cameras are not showing us how cautious they are being.
Denise & James Earl, Logan & Chris and Tiffany & Krysta have already had their close calls by being spared elimination or by almost being eliminated, however they only seem to get ahead when the challenges suit their skillsets, whereas the Green Team is more versatile. Logan & Chris could be a strong team if they stopped being so impulsive and communicated better with each other, but it seems their lack of communication will be their downfall.
Kelsey & Joey are realistically the only competition J&D have remaining. However, the news anchors need yet to face their close call so that their inner fire lights up. They just need the extra push.
In the event that Justin & Diana don't make it to the final three, the odds are pretty even for everybody else.