dead ball balk?

[Atl Blue]

Since the ball was dead, there could be no balk. The hidden ball trick is IMPOSSIBLE following a dead ball as the ball has to be in possession of the pitcher, on the rubber to be put back into play.

You were correct in your call. How you tell the other ump depends on MANY factors (how well do you know them, your working relationship, etc.). In this case, you had a rule problem, it had to be corrected or there could have been a protest. You were right to let your partner know there was an issue. I hope you did so tactfully, which usually means calling time and going to your partner and talking in private. Let your partner make the correction.