I've read every word of the UT study, and from my training and experience believe I understand them. They certainly identified areas for improvement--leaks that could be remedied and likely for a profit or at least low net cost. However, unlike virtually every study pointed to by opponents of fracking, this one examined real wells, up close, during the various phases of completion and operation. That means that unlike all the overflights with model-based interpretations, very few assumptions were needed, and most of those were verifiable.
Of course it's true the producers agreed to participate, so the study wouldn't include those with anything to hide. But the ones that did participate are among the largest shale gas developers in the business, including Anadarko, Encana, Pioneer and XTO (ExxonMobil). The numbers speak for themselves. This wasn't a snapshot view of a few wells, but a detailed look at 190 sites, including "Measurements of active equipment at 150 production sites with 489 wells, 27 well completion flowbacks, nine well unloadings and four well workovers were included in the study." No other study I'm aware of has a sample size within an order of magnitude of this one.