Seems like we've seen this thread before... Michael, you are correct. Now, I'll try and overly complicate it for fun.
If the throw goes into center field, but in your opinion the runner would've been safe at second with a good throw, you rule a sacrifice bunt and would only score an error if there is an advancement beyond second. What I mean is, the pitcher makes the turn to throw the runner out at second when he had no chance of retiring him. Good throw / bad throw, its a sacrifice (0-0), batter reached on the Fielder's Choice of retiring the runner at second. This is an old argument I don't really want to start again.
If instead you believe a good throw would've retired the runner at second (and he made a bad throw), or if there is a bobble on a come backer and everyone is safe where you REALLY believe the play at second would've been made, then its an E-1 and FC (0-1 on batter). In the later case, the ordinary effort play would be to go to first, so I would have to see the pitcher turning to second before the miss-play with lots of time to not credit the sacrifice, like he drops the ball transferring out of his glove. I'm going to score this one a sacrifice, reached first on E-1 (0-0 in the stats) almost all the time. If the pitcher boots the ball with his shoulders square to the plate (assume everyone safe), then its definitely Sacrifice (0-0), batter reaches on E-1.
Just my opinion....