Could be any number of things I guess; dropping your bow arm in the excitement of the shot, arrow deflected by something, hunting clothes could have interfered if you're not used to practicing in them, your sight pins got bumped on the way to your stand(have you checked them since?), etc.
But my first guess would be that the shot was further than the 25 yards you estimated it to be.
Just a guess. Maybe others will be more helpful.