I think the Bills have also benefitted from favorable officiating to a lesser degree, but it's probably not going to mean much. Ultimately, the problem is that the Chiefs have been limping along for an entire season and, even after their lone (meaningful, sorry Broncos) loss to Bills, they didn't noticeably improve offensively. Even with favorable officiating, they haven't been able to have any kind of breakout game, and the playoffs isn't a likely time for one to happen. It's going to come down to defense and they're one bad game away in the part of the season when defenses are most likely to get exposed.