None of the study results were robust, but many of the study outcomes were positive. So they were counting up positive outcomes and saying that more often than not, it was evidence that Ivermectin was effective.
This is a good means of generating a hypothesis, but a bad means of generating a conclusion.
Most of these studies were not in any way controlled or comparable in their conditions, and some had a very low number of observations. It didn't seem plausible that the data could be aggregated together.
It will be very interesting to see the results of the larger RCTs underway. Regardless of the outcome there _has_ to be a lesson for at least some people who arrived at fervent conclusions about what a miracle/scam this particular drug is. Unfortunately it seems unlikely that it will be a lesson that endures.