Although it's way-too-common to have a canted barrel on late-model Ruger Single Actions, I have never seen a front sight on a "Six" series revolver canted from the factory. Maybe somebody did it on purpose for personal sight regulation. I would be more concerned that it twisted itself. If so, it's possible that it would continue to do so. So...I would shoot it, with heavy factory loads, and pay close attention to any further movement.
Personally, I could not live with it, and would persue a correct solution.
WAYNO.