[AtlUmpSteve]

To add on:

One of the still-remaining myths of the game is that umpires can call a batter out for throwing a bat; that is only true if it interferes with a play. It doesn't matter that it hit the catcher or the umpire, or if you have warned them. But, so many rec leagues have rules aout it that people believe there is such a rule.

You also cannot use the God rule which only applies when/if there is no specfic ruling. It is not an out, you cannot make it one. You can eject/restrict the player if 1) done deliberately, 2) done carelessly, or 3) endangers another player. Personally, I prefer referencing #3, if a repeat performance.