I made a similar mistake grouse hunting once. A grouse flushed with the ussual vigor and commotion common with a Ruffie coming out of thick cover. As it came into an opening I shot and dropped it cold. Problem was it was a spruce grouse, and not a Ruffed Grouse. Had I been 5-6 more miles north in Canada it would've been legal, but not in NH. I felt terrible, and had I encountered a warden would have confessed, and taken my lumps. Having not run across a warden on the way back to camp, I decided to do the only other sensible thing. I ate the evidence. It was delicious too. Needless to say, I pick my shots differently.