Serving as an expert witness for the poultry companies being sued by Oklahoma, Bierman pointed out missing files, different versions of reports showing different test outcomes and one report that left out half of the 1 million-acre watershed, according to AP reports. He pointed out that Engel sent follow-up reports to correct the errors, but that the follow-ups had different numbers and new outcomes. Bierman told U.S. District Judge Gregory K. Frizzell that Oklahoma's model "can't tell the difference" between real amounts of phosphorous and "numbers that are completely made up."