[Cub42]

That is a judgemnt call, and someone will not be happy. You mentioned there had been a number of sweeping curves thrown. I will give the batter the benefit of the doubt when hanging in against curveballs. But I wasn't there, you made the call. Here are a couple of ideas to help you in these situations:
1)Whenever a batter is hbp, call " time, time" instead of deadball.
2) If you are going to hold a batter from first, Be very emphatic about it. Leave no doubt you are 100% positive. " Time, Time, Batter stays right here" You have to sell this. Call it right away also.
3) Never got to your partner, or to someone in the stands and talk about a crucial or controversial call. It will leave the impression you are having second thoughts, or are unsure. Discuss these after the game. This will prevent any uncalled for challenges in the future.