Cobalt has been blown out of proportion by racing regulators who have dragged the industry through the gutter, trainer Peter Moody has told an inquiry.

Moody admits he still has doubts an oral hoof treatment caused Lidari to record a cobalt reading almost two times the allowable threshold after his second in the 2014 Turnbull Stakes.

But he said he had no other explanation as he did not believe something untoward - such as a race-day injection of cobalt - occurred.

Moody's defence argues stablehand Rami Myala for months mistakenly gave Lidari seven times the recommended quantity of Availa, a hoof powder containing cobalt, and Moody played no part in it.

Moody denied suggesting to Mr Myala or his chief feed man Neil Alexander that Lidari must have been given more Availa than was initially disclosed to stewards.

Racing Victoria stewards' barrister Jeff Gleeson QC said he will tell the Racing Appeals and Disciplinary Board not to believe the defence story.

"No talented trainer with a passion for horses, who is up before dawn six or seven days a week, in the stables, would ever conduct themselves in the way you're asking the board to believe," Mr Gleeson said on Friday.

Moody responded: "I would put back to you the person in the same situation wouldn't find any reason to cheat."

Moody said he did not believe the elevated cobalt reading was a serious concern until he was charged in July with administering a prohibited substance to affect the performance of a horse in a race, which carries a minimum three-year disqualification.

"That rule's been brought in so a trainer can never walk free, so a trainer must be penalised," Moody said.

"I still believe cobalt as a drug has been blown out of proportion."

Moody said he believed cobalt was a "non-issue" in racing and the cobalt rule was brought in with little education for the industry.

"It's my belief, and for the sake of the industry which has been dragged through the gutter, that this should have been done pre the rule being brought in and participants educated properly.

"I think unfortunately cobalt is a big balls up and it's going to play out for a lot of years, not only in my case but in the industry's case."

Mr Gleeson said for the defence explanation to be believed, the RAD board would have to accept Moody was clearly incompetent and grossly negligent in the lead-up to and aftermath of Lidari's elevated cobalt reading.

Mr Gleeson suggested the reason no one initially told stewards Mr Myala was feeding Lidari five-and-a-half days out of seven was because he was not doing that.

Moody disagreed and has said his team did not realise until later that Lidari was in a different barn before the Turnbull Stakes where Mr Myala handled most of the feeding.

Moody denied making up evidence about his conversations with Mr Myala.