If he didnt break a rule theres no way it was cheating, never seen it done before so that was a first.
As for disadvantaging harris, no there was plenty of more dirt by the fence for him to use he just didnt do as much gardening as the other 3. And surely gate 4 is the best gate towards end of every meeting because all the dirt builds up on the fence therefore gate 4 will always have more dirt to play with.
If u was 2 time british champ, world champ and currently leading world championship sure you would be slightly arrogant too probably helps him stay focussed on his job.