Keep in mind, most of what I've coached is kids matches at the local tournament. And those are chock full of their own issues, let alone the crazy rules.
I've seen the chest and head sensors in the wrong gear, the blue and red sensors on the wrong person, badly calibrated sensors that basically give one person the match. In the colored belts, they usually have regular hogus with the corner judges keeping score, and I've seen where on Mat 1 you have a score of 2-3 every match, and on Mat 2 you have a score of 25-34 every match...from fights with a similar amount of contact.