This is my perception of figure skating judging: the biggest error a judge can commit is to give scores that are outliers compared to those of the rest of the panel. So you give marks, in part, based on what marks you think the other judges are going to give. When Kaetlyn was underscored in the short (first skater, in her first GP event, not unexpected that the judges would lowball her), I'm betting what goes through a judges mind is "oops, I bet the other judges are going to boost her PCS in the long, guess I'd better do that too." And so they over-compensate, based not necessarily on the skating but on what they think the other judges will do.
The only politics at play are of the peer-pressure variety. Not even direct peer-pressure, but perceived peer-pressure: I have to guess what the other judges are going to do, and do the same. If I don't, I risk getting a black mark against me and losing my cushy judging assignments.
There you go: a rational explanation for irrational judging!