She’s almost certainly committed perjury, but it seems to have been decided that charging her might prevent genuine cases from being reported. Personally I think that can be addressed by charging her, and making it very clear why in her case it’s justified - this isn’t a woman who made an accusation that could not be proven because of a lack of evidence - this is a woman who a judge said explicitly that she was unreliable and untruthful.
It’s a shame that true justice will not be served in this case. I have always thought that false allegations deserve punishment.