Do you suppose that all of the nonresidents knew they were illegal?
How many of us have hunted out of state and just did what the "outfitter" told us was necessary? You need this, this, and that. Not all of them were charged with the same offenses. Some knew they were wrong, I'm thinking not all of them did.
Scenario: Shady outfitter tells client, "It's shotgun season, you can party hunt and tag your deer with someone elses tag." Client looks at regs and sees that it is allowed but doesn't look any further to get the specifics, placing his trust in the outfitter. Client is charged $xxxx, shoots a deer, then is handed a tag to put on it. In his/her mind they were legal.
As in the case above, I would think a lawsuit against the outfitter would be forthcoming.