Regardless of what the umpires thought of Utley's slide, how did they not notice that he never touched second base?
Rule is that they recreate what likely would have happened if call was originally correct--in this case fielder didn't touch bag. What would have happened? No-call/play still live (like when runner from 3B slides past home plate without touching plate and catcher misses the tag--ump stands around until one or other happens). Likely Utley goes back to touch bag with a no-call--when saw ump calling him out--moot to touch bag at that point. And, Tejada obviously wasn't going to get up and make a tag before Utley touches bag.
My take on play is that it was a dirty, unethical semi-slide (more of a rolling block than a slide) but "legal" under customs of the game, if not letter of the rules. Seems like umps only care if any part of sliding runner can touch bag (even if doesn't actually touch). Dirty because no primary intent to reach bag but primary intent to initiate a collision and reasonably forseeable to cause some form of harm to fielder.
Unfortunately, this is way game is played today, especially in crucial playoff, one-run, late inning situation. MLB should change how rules interpreted in this type of play. Terrible. Maybe something will happen as a result.