Problem with a lot of judges is they make assumptions about a beer that they have no way of knowing. Sometimes they are right and sometimes they are wrong.
If they had said "this beer has a sweetness that is distracting and seems out of place in the style." That would be a good comment. They said what they tasted and that is all you can ask of judges really. They could even go on to say "this could possibly come from underattuation." It would make the judge look like less of a dope.
Getting weird flavors in beers like this is more or less just one of the things you have to live with in judging. Assuming the judge knows what sweet tastes like, I would have to say when he/she tasted it, they tasted sweet. Was it because the beer is sweet? Well, maybe not. Might be b/c the beer before was super dry and bitter, maybe b/c they were wrongly picking up some heavy hop resin (as suggested above). I once judges a flight of beers and somehow by accident 2 of the same beer got in the flight. Gave 1 a 20 and one a score in the high 30s. Picked up strong off flavors in the lower one. Was it a bad bottle? Maybe. Maybe not.