You're probably right about them lacking hunting licenses but what makes you think they didn't see the cartoon and weren't on Wyle E. Coyote's side? I was. I wanted that mangy mutt to obliterate that arrogant, elitist, sticks his tongue out at everyone bird. Those two saw that opportunity and acted in revenge!
On a serious note, I'm sure they knew what they had, they couldn't possibly be that dumb. I just wonder what they were going to do with them, there's almost 0 meat on those birds...