I have read that it was over a difference of opinion between him and the Fish and Wildlife Commission and that he was a professor of wildlife management at the University of Idaho at the time he was hired in 1938.
The information you have read about Dr. Hatch is correct.
In March 1939, at the time of his appointment to Director of the Idaho Department of Fish and Game by Idaho’s first Fish and Game Commission, Dr. Hatch was Professor of Game Management at the University of Idaho.
Commission meeting minutes of April 1939 reflect philosophical differences between Dr. Hatch and the Commission. The Commission felt it was in the best interest of the Department and Idaho sportsmen that Dr. Hatch resign.