On today's ride there was a rider approaching who turned right onto a lane which is a Strava segment, I turned left onto the same segment about 10 yards behind him, it was going South so we had a bit of a tail wind, it was 0.33ml by the time we got to the end of the segment I was on his rear wheel, but Strava had me 3 seconds slower! is this down to how different GPS devices record?