"Complaining" as you put it, helps shift cultural norms of violence against women and sexual assault.
Taking that one word out of the context is hardly a basis for making any reasonable commentary. I have suggested there are actions that can be taken to ensure the police have a reasonable basis for formal action against someone who commits an assault. Airing ones grievances about police inaction, not something that the OP did in this case, but has been a regular feature of similar posts in the past, is not one of those actions.
The advice given here on this forum has been consistent over time. When members post here to inform members that there is an issue about some places or individuals, they are encouraged to report that. Today, they are encouraged to use the AlertCops app if they are in Spain.
Where an assault has left them feeling distressed, or even worse, resulted in physical injury, they should seek medical assistance. If they want formal action taken against an alleged assailant, it appears that a medical report is a critical component for the Spanish police that allows them to initiate formal action. As travellers from outside Spain, most of us will never understand all the nuances of these things, but I think we can help women by informing them about those we know about.
These are distressing events. Perhaps not as much for the OP personally in this instance, who was reporting someone else's experience to inform others here about the issue, but clearly for the woman who experienced it and any other person this might happen to. Unfortunately, it seems that many perpetrators will go unpunished when sexual assaults are not reported in a manner that allows police to take formal action. I don't think this is the place to go into the myriad reasons this happens, but I see it here in Australia, and I presume it happens elsewhere as well.
That said, if someone does want to see a matter like this pursued formally, I can only imagine the added distress of finding out they haven't done something that is required under Spanish law that would allow the police to do that, and that this cannot be rectified. I think we can do better than that, and offered at least some advice on how that might happen.
@truenorthpilgrim, circling back to your comment, I am prepared to have my views on this and other matters challenged, but I don't think that taking one word from a sentence or a post and presenting it out of context is any reasonable way to do that. Whether your point is reasonable or not is a quite separate discussion, but not one I think I need to pursue at the moment.