Part of the reason why I play random MP games is to try and stop newer players from posting threads like this where people are accused of cheating (the other part is to show players that there are people with legit averages who don't quit MP games).
I dropped a 28 the other day in a random MP round with a couple of decent Pro tier players, and one of them remarked that "it's nice to see it can be done" in regards to my score.
Do I shoot a 28 or 29 everytime I play? Hell no. Then again, the game wouldn't be as much fun, IMO, if I could shoot like that everytime on the course.