Sounds to me like a training issue, not a horse issue. I'd get away from that bit as it can be VERY dangerous and incredibly painful. Also a few more incidents like the one you already had, then your horse will have scar tissue and will have SERIOUS bitting issues when his tongue is all scarred up.
If you need more control in a field, learn how to use your leg to move his hind end over, haunches in, leg yield, circles, get him to pay attention. If you aren't able to do this with him then I highly suggest that you find a trainer to work with who can work with both your horse and you. Overall that bit can do a lot of damage and there are far more less harsh alternatives to riding a horse safely without a bit of that caliber and danger.