So just for fun (ha), and after being inspired by the pitchfx thread earlier today, I decided to fire up gameday and take a look at Tejeda's pitches. I've heard about how maybe he's a AAAA pitcher that can fool AAA batters but not major league players with the location of his stuff. I was also curious as to whether all the pitches were that poorly located or whether the ump was squeezing us.
So in looking at all of this, it looks like a little of both was at play, assuming that the gameday pitchfx system is accurate. Tejeda's first pitch of the game, specifically, looks like a strike to me according to the image. That said, there were plenty of balls thrown that were legitimately not strikes, so the ump can't really be blamed here.
As an aside, this one at-bat really pissed me off... but also, if you wanted to find one at-bat this decade that sums up everything the Oakland philosophy is all about, this would probably be it: