Riding Rules (325:60-1-19)
In a straightaway race, every horse must reasonably maintain position in the lane in which it starts. Each jockey shall be responsible for making their best effort to control and guide their mount so as not to cause a foul. The stewards shall penalize riding which results in a foul. If a foul occurs because of a jockey not making their best effort to control and guide their mount whether intentionally, carelessly or incompetently the jockey may be penalized.

Stewards to Determine Interference and Placement
Quarter Horse, Appalooa, Paint Races (325:60-1-20)
The stewards shall determine the extent of interference in cases of fouls or riding infractions. They may disqualify the offending horse and place it behind such other horses as in their judgement in interfered with, or they may place it last. The stewards may determine that a horse shall be unplaced.