I wasn't there but I just spoke to someone who was there and the balk was actually called on the catcher. From what I gathered, runners on 1st and 3rd, 2 outs, the runner on first started to slightly jog to 2nd to try and induce a throw to maybe score the runner from 3rd. PNG catcher stood up out of his stance thinking that the pitcher was going to try and throw the runner out. But the pitcher made the pitch instead and the catcher got back down in his stance and made the catch. That is a no-no. Had the catcher remained up in his stance no balk would have been called. It's still a pretty crappy way to end a series.