Saw this last week and all the D3K talk made me think of it.

Batter has 2 strikes, next pitch hits the ground and she checks her swing. PU calls ball.

Batter thinks its D3K and runs for 1B, catcher's throw beats her and base ump points to 1B and calls her out.

Bedlam ensues and BU offers the explanation "she's out because she ran", but never mentions an appeal on the check swing. The PU did not appeal the check swing.

Wouldn't this fall under the "not a batter runner" category where the batter was not yet qualified as a runner and could not be put out.

Maybe he was calling her out for interference (running and drawing a throw sub-category). It doesn't apply to the D3K situation (by rule), but at least that call would be understandable.

Unless there was a request for help from the PU, the BU can't just declare the ball to be a strike and rule the now batter-runner out.

But Tom, if the player is still a batter, she cannot become a batter-baserunner unless the PU surrenders the call, which he didn't, the way I read it. If you're not a batter-baserunner, you can't be called out for interference unless there is another runner on base and you impede the progress of a play on that runner. That wasn't mentioned here.

The rule on running to draw a throw only applies to a player who has been retired. In this case, the batter has not been retired.

A little preventive umpiring would work here.

When the batter takes off to first, kill the ball. If there happens to be other runners on base, hesitate to see if the catcher has a legitimate play and then kill the ball if not. No matter what, the batter is returning to the box.

Yeah, I know. I was just reaching for some straw where his explanation might have made some kind of sense (still wrong, but at least you'd know where he was coming from).