I can't take any of them seriously since I saw one of those fencing events where they kept pausing just in time so there was one second left on the clock repeatedly, basically taking advantage of rounding to full seconds to drag things out.

Yep, judging is always subjective. It's what that specific judge (or panel of judges) saw, weighted against their own biases, both in the sport itself, and the players/teams/countries competing.

Unfortunately, that means results are often unfair.

This case is particularly egregious because it seems like the judges actually agree they made a mistake, but the correction was appealed purely on pedantic adherence to procedure.

I.E., no one is even disagreeing that she should have won the bronze if her performance was judged accurately.