That image is saying the pitches were 3" off the plate. That's a fair amount. That's not to say that Posada shouldn't have been swinging with two strikes, but those pitches weren't that close. Strangely, the ump had kinda/sorta been calling that pitch all night, but only for KC pitchers. (Eight pitches called strikes for KC pitchers in that location vs. only one for Yankee pitchers.) It's pretty bad, actually.
Just because umpires often make bad calls doesn't excuse last night's ump for unilaterally turning the last at bat of the game into a strikeout. As I said Posada should be protecting the plate with two strikes, but it doesn't change the fact that the ump completely let Soria--who couldn't buy a strike--off the hook.
