Lies and denials have highlighted the final day of the hearing into cobalt charges against trainers Mark Kavanagh and Danny O'Brien and vet Tom Brennan.

The Racing Appeals and Disciplinary Board heard final submissions on Friday from counsel representing Racing Victoria stewards, Jeff Gleeson, Damian Sheales for the two trainers and Adrian Anderson for Brennan.

Gleeson said the case against O'Brien revolves around a series of lies while Sheales went about putting those lies to bed.

And Gleeson said the one big lie against Kavanagh was that he was the beneficiary of Brennan's philanthropy in maintaining he did not pay the vet $3000, nor did he know the contents of the Vitamin Complex bottle.

Sheales said Kavanagh and O'Brien had been dragged through the public arena in the cobalt saga which has become very bitter.

"There's been no change of the story, there's only been an addition," Sheales said.

Sheales said since O'Brien's interview with stewards on January 14 the trainer has maintained the same story throughout his evidence.

"It's the observations of a man with a clear conscious," Sheales said.

Sheales said charts detailing the drip regime, given there were 120 drips given in the two stables, were a telling factor for his two clients.

Gleeson described Brennan as a talented and intelligent vet but said he hid the bottles of Vitamin Complex from his fellow practitioners at Flemington Equine Clinic.

Brennan has admitted adding Vitamin Complex to supplements in IV drips but has denied knowing it contained high levels of cobalt.

Anderson told the hearing the board could not be comfortably satisfied Brennan knew cobalt was being administered to the horses.

The verdict on the three will not be handed down before next Friday.

Brennan is appealing a disqualification imposed by Racing NSW stewards for his involvement in the case against trainer Sam Kavanagh who is also fighting a ban.