Well I personally dont think he will produce another sample like that because 8 experts have agreed the likely explanation is microbial contamination combined with the fact that they have tested other samples from him and they have not behaved the same way. So to me, the only way the same thing could happen is if microbial contamination occurs to a further sample taken.
Of course the experts may do more research and come up with a definitive cause, in which case it may happen again and then I think that information would give an indication on what could be done to either prevent it in the future should it arise again.
Brendan - If the sample rose after retesting and then got to a level where it rose no longer, I still dont think they could confidentally say what the actual level was when the horse was initally tested.
I wonder if the levels rose exponentially or would they have then been able to pinpoint what the level was at testing if that were the case?