actually won in 149 a few back
so yes sometimes a trainer can find a key to a horse or make some changes to shoes, feed training etc, it can and does happen
however when the turnarounds are significant( as in this case) or one trainer has a few of these similar type it needs to be investigated
drop by where des trains and observe and ask him what he thinks was the reason for the big improvement
test the horse in question after every race etc
i mean agco judges etc just do something