I was wondering that, myself.
Not having seen the suspect or the woman, and not knowing what they look like, I'm not sure how obvious it was that the suspect was a man, and the woman was not.
Just yesterday, looking around at people at restaurants and stores, there were several whose gender was not immediately obvious. Often, this was due to extreme obesity making normal characteristics difficult to observe. PC or not, it's hard to tell when body shapes are amorphous.
Also, there have been recent robberies where the "man" was a woman (in hoodie, ballcap, and sunglasses), or the "woman" was a man (cross-dressing). It would depend, I suppose, on whether the suspect's identity were known, or if people were responding to a general description, as to whether a woman would obviously not be the suspect.
icedog88, going back to judging people - we are talking about snap judgements based on appearance. We aren't talking permanent judgements. If the person dressed in a manner that puts us on edge turns out to be polite, friendly, and pleasant, it's not hard to overcome the initial apprehension. But the point is, the initial appearance in this case is something that has to be overcome. (And it's not a racial thing; my bells and whistles don't go off over conservatively dressed black males, but they do over white males in hoodies and baggie pants, assuming no major behavioral cues are happening.)