*Update* The best guess here is that from grabbing the raw Pitch FX data, one of the pitches in this at bat was dropped. From video review, there was no true error by Jerry Meals.
I'll have more on Shields later today, but for now, here are all the pitches that landed in Zone 5 during the playoffs from 2007-2014 (Pitch FX era).
Jordan Zimmerman 10-08-2012 vs Matt Holliday (Cardinals) - Fastball
Outcome: Holliday grounds out to second baseman Danny Espinosa
Cole Hamels 10-04-2011 vs Ryan Theriot (Giants) - Fastball
Outcome: Theriot singles to a line drive to Hunter Pence
Carl Pavano 10-07-2010 vs Derek Jeter (Yankees) - Fastball
Outcome: Derek Jeter strikes out
Cory Wade 10-01-2008 vs Ryan Theriot (Cubs) - Fastball
Outcome: Theriot grounds out to James Loney
So in the history of bad zone 5 playoff calls, Ryan Theriot has been the batter 40% of the time. Hunter Pence has also been involved 40% of the time.
Shields call was arguably the most obvious strike of all of them. All the other calls have been fastballs, while Shields poor call was a knuckle curveball. It's probably easier to call a fastball as a ball/strike than it is a curveball.