Brian
PANEM ET CIRCENSES
The pitcher determines the pitch. The catcher just makes the calls so they are both on the same page.
Sometimes. There is a lot more to it than that.
Boxberger threw his second best pitch to a hitter that he had 0-2. If you are going to throw that pitch, in that count, with the tying run on base it had better be in a location that is either Ball 1, fouled off, or hit weakly.
It appeared to me from the sequence that he threw to Zobrist that he was having trouble locating his changeup. I'd bet on it, but I also don't know where the location was asked for.
That 0-2 count was the perfect time to try and throw another change. Then again, that late in the game the pitches are often called from the dugout.
FWIW - Relievers often defer to veteran catchers. Especially when they have called the entire game.