In a game this afternoon, there was a play where the batter made a sacrifice bunt to the pitcher, advancing the runner from first to second with the batter thrown out at first.  In the notes, the play was deemed a '-' (Poor) play.  The poor play was on the pitcher (not important, but his second of the inning grr), so my guess is the decision was if he fielded it better he would have gotten the lead runner?  Intuitively, I think of getting the lead runner on a sacrifice as an exceptional play (and therefore not getting the lead runner isn't a bad play), but perhaps the bunt was such an easy come-backer the play at second base would have been a given had he fielded the ball cleanly?

I think your guess is the answer. Normally I don't believe the pitcher will try for the lead runner unless he's pretty sure he's going to get him. In these instances perhaps the sim "thought" both lead runners should or could have been thrown out. I agree though, it seems like odd calls.