I read the rules yesterday and agree Tetrick did everything right, however part of the time he was off stride he was barely losing ground. The judges felt as long as he was off stride he should have lost more ground.
I saw the same thing happen at The Meadows a long time ago, a horse broke early in the race, was off stride at least 10 seconds, came back and won but was DQ'd for not losing enough ground while on a break. In the rules for a breaking horse it says, a horse may be disqualified and placed last for an extended break which is exactly what happened yesterday.