She used the app for 5-6 months, presumably with other people having been scammed repeatedly in the past and having reported the app. Then after she reported it to the CFPB (which is an independent government agency dedicated to preventing these types of scams and other abuses of customers), the CFPB spent 3 months of back and forth with Google before they were willing to take it down.
So the argument is that the app was up for several months with the US government directly reaching out to Google and pushing for them to take the app down for being a scam but they ignored that as long as they could and likely ignored plenty of other reports in the past.
At least personally I'd argue that's gross negligence.