I've worked with a midwife or 2 that have completly shown me up in front of the women and in normal circumstances i would have answered back, but i've made sure that i bit my tongue and got on with it so not to get a reputation for myself.
Without knowing the circumstances i would either:
explain the situation you found yourself in and defend yourself or
eat humble pie and apologise if you feel her complaint stands up.

But don't let it get to you, its hard work to get on the course and not worth throwing it away over this.