The Lacey Act is not a law to tangle with. Felony Lacey charges can run into tens of thousands of dollars, and seizure of involved gear, like guns, vehicles, etc. The Law was intended to address commercial hunting, and the movement of illegally taken game across state lines. But it is often used to address aggrevated poaching cases in places like National Parks and National Forests and other US property. I did not read the link, and cannot say why Nebraska AUSA office went with Lacey in this incident. Typically though, Lacey is used to "hammer" special cases.
Misdemeanor Lacey charges are a bit milder in penalties.
Crossing state lines with game legally taken should not result in Lacy charges.