Let's say the booster has a brain and is using it. Instead of running away into another room and keep boosting wins, he's only going to boost a certain number of spar wins (and loses), keeps a ration of 1,x and isn't doing it obvious at all.
The goal is to get a lot of spar wins and not to have a good w/l ratio, he would also lose on purpose so it' not that much obvious.
I'm not sure if anyone would reset someone for a 1300-1300 score, it doesn't look boosted at all (boosting spar wins and loses alternately).