I've always looked at it as a difference between being prepared for self defense and hunting....
If I head out on a country road with a hand siren to try to locate Coyotes,,,it's obvious that I'm not hunting, but I'm still armed... If I'm hunting, I'll have enough goodies with me that there is no question...
Most game officials will observe what you are doing before approaching...hopefully they can tell the difference between a caller and a hunter...Now if you hit the fields after dark with a spot light, rifle, camo and all the rest of the goodies,,, I can see where you might be mistaken for a 'hunter'...But in normal street clothes with a caller and a holstered carry side arm, it would be a different matter..
I'd certainly contact your local game officer and discuss the matter with him/her...I know that when I talked to our local officer about using a Turkey call for Coyote hunting, he gave me the same advice to avoid being suspected of Turkey hunting out of season...Just let them know generally where you will be...