Classy move. In today's Paine-to-Pain 13 mile (chiefly) trail race in Westchester County, just north of NYC, the guy in the lead stopped right before the finish line. No one knew why. He had been in third when the two leaders made a wrong turn in the final 2 miles. The course was well marked (I ran it) so it was their fault and presumably the result of fatigue in missing the yellow markers. (Volunteers ran the course beforehand to make sure everything was in place.)
In any case, while there may be those who say tough, as I sometimes would say, and that the guy would have been forgiven for not stopping, that he did is a fine act of sportsmanship.