How to determine what a pronoun is referring to

From the stated example, the parenthetical "who had been working under an extremely verbally abusive supervisor" is separate from the main idea and is added to clarify the identity of the first woman mentioned. The second time a woman is mentioned it is most unlikely to be the same one.

Without the middle part the sentence reads, "One woman [..] confronted the woman and was abruptly fired from her job." Apart from sounding a bit tinny to this ear it works just fine to get the meaning across.

We may be overly used to clarifying that we are talking about a woman, not a man, these days and that's fine. We should not be surprised when we end up talking about more than one woman at a time.