I agree with Alanti. I think a natural explanation for this was that you had an abnormally high amount of downhill putts or putts that went downhill beyond the hole during the course of the round. There are times when I leave it short a lot or blast it by during the course of the round. Just realize what putt you've left yourself -- is it above or below the hole? Is it hole-high (play enough break)?
In the end, you probably had a high amount of downhill putts during the round. Just make sure to check the elevation past the hole. I generally check up to 8 ft by the hole to get a good idea what the putt is doing. Good luck