I put this video up here for informational purposes and not to imply anything about Travis Bagent. He is a great arm wrestler and a world champion. My point, though, is that refereeing an arm wrestling match - even at a major competition - is an inexact science at best. Further, it seems that those wrestlers who are more experienced and more widely known are given "the benefit of the doubt" much more often than lesser known wrestlers.
In the video below, which was stopped due to a slipped grip, notice that Bagent's elbow appears to come off the pad two different times within a few seconds - and yet no elbow foul is called.