Mate, you're an idiot!!
With the amount of dogs they take to the track, is it not possible for a couple, out of "x" amount of runners, to be injured prior to race day.
I know it is trainer responsibility to prepare their dogs in the healthiest and soundest of manners.
It reads like you are trying to impose that they are race rigging to suit themselves. If this is the case mate, you need to be checked by your local Mental specialist.
Out of all the runners they produce to the track for race day, it is possible, after all, we are all only human, to have things NOT go our way, by the means of injuries or so on. Could've slipped the collar before entering the vehicle, couldve hurt itself in the kennel on the way to the track...
Like winners, there are no certainties!!