The report that she had time to put the magazine in her gun and racked the slide after drawing it would seem to indicate that the man did not present an imminent danger of serious harm.
Time to put a mag in the gun and charge it isn't hardly a good criterion for whether or not she was in imminent danger. Her life could have still be threatened and she had time to react and load her gun for whatever reason, if anything just because the flasher was inept or otherwise busy (as previously noted), had he had bad intentions.
I certainly know folks who can load and make ready a gun to fire quicker that others can draw from ankle carry. Would that mean that if you have the time to draw from ankle carry that you are not in imminent danger?
I do agree that she wasn't in any apparent imminent danger. The flasher was not reported with any sort of gun or knife, did not threaten bodily harm, and more importantly...
He allegedly sat down and began performing a sex act and said she should watch.
If he is sitting, he can't kick her. Sitting and doing what he was doing does not indicate that he is about to jump her or otherwise give chase. No knife, gun, or any other type of projected force weapon was seen, so following typical self defense instructions, she should have been watching his hands if anything and seen the lack of weapons he could have used to hurt her from his seated position.
He was a perv and she drew down on him. Personally, I don't see the need for it. The only known threat was visual-only and easily mitigated. He wasn't threatening anything to her or her belongings. I think most people face greater threats commonly in shopping situations (Black Friday will have several), driving (road rage), and social situations such as at bars or parties where actual threats are made by people who are angry, but those are situations where drawing down on a person would not be appropriate at all in most cases.
That this guy might have done something more (assuming he must be a rapist because he is a flasher) isn't sufficient for drawing down on him either. No doubt we encounter people every day that might do something. To assume he must be a rapist because he is a flasher would be like assuming that because somebody got angry with you that they are going to kill you. After all, people suffer severe bodily harm and even murder as a result of confrontations that start off with just some angry words.
Probably the most prudent action which was not taken by the woman would have been to immediately start putting distance between herself and the pervert, taking her child with her thereby mitigating the threat to both. She could still have been drawing and readying her gun during that time and that likely would have been most reasonable given her apparent fear. Remaining in proximity to a perceived danger who has not threatened you (or one who has) is not prudent. She was not trapped in a confined space such as an elevator that would have made it necessary for her to remain in place.
She may have been 100% within the law to do what she did, which is great if that is the case. Hopefully with all the time she spent with the guy, she had a chance to get a very good description of him.