That is probably the case; however, it doesn't mean that liars don't exist in our circles. Clearly, we do have perpetrators of abuse who exist, and we probably also have people who are chronic liars too.
If the culture changes were speaking up is encouraged, then the social cost for doing so will rapidly decrease or hit zero, and then we will also be dealing with a lot more false claims. I have said that, currently, we can expect false claims to be very rare, but that is a "luxury" we might not have in the future - therefore, we need to act on the claims we get right now, quickly.
I would hesitate to quote this as fact. Actual false claims are a lot higher than that, according to some sources. That doesn't mean that we shouldn't give victims the benefit of the doubt and try to get to the bottom of things; it does mean that the fact someone makes a claim doesn't automatically make it true.Even outside of Mennonite culture, the reported allegations that have been proven to be false is 1-2%.
Doubling down on claiming that everything an alleged victim claims is true won't get us anywhere good, and as I have said before, a lot of victims never speak out at all. We need other ways to identify and catch perpetrators. We also need to be aware that false claims do happen, and will happen, and not to let that stop us from catching and dealing with perpetrators. The primary source of information should never be a victim alone, and in legal terms, that's not enough for an indictment and a conviction either. There is often lots of evidence elsewhere.