I don’t know anything about this horse or person, but I was curious so in case this is helpful context for anyone else:
The NRHA allows administration of this drug as soon as 30 minutes before a competition. So a trainer could be reasonably assured that it could safely achieve a competitive edge? But that trainer could also be reasonably assured, (I think?) that a drug screen would come up positive. So why would any trainer risk that? I can see trainers trying to get around with things that “don’t test,” but this doesn’t seem like that. Would they really just roll the dice? That seems unlikely to me.
But if the farrier used it a couple days before the show, it might test. I appreciate the differing opinions on the plausibility of that and whether that person would likely know that they were within 7 days of a show and shouldn’t use it.