You're right, all of you. It seems, though the right way to go about a search is to ask first.
Most of us, the ones with nothing to hide, wont mind all that much. If someone does refuse, then the warden can, at his discretion, request a search warrant if he has reasonable cause to suspect a poaching violation. All the while detaining the suspect until back-up or the warrant arrives.
It makes more sense to allow the inspection and get on with the day.
There's no difference between a game warden and any other deputized officer, they're bound by the same constitutional restraints as any other agency.
Illegal fish in a film cannister??