His bad behaviour has cost John Singleton $15,000, but much more in terms of friendship and trust between himself and his former trainer Gai Waterhouse.

After two weeks of publicity over the performance of his mare More Joyous in the All Aged Stakes at Randwick on April 27, Racing NSW stewards said on Monday they were satisfied there was no evidence to suggest the trainer's bookmaker son Tom had passed on any inside knowledge that there was a problem with the horse.

Information Singleton received on race day from former jockey Allan Robinson was that Tom's colleague from the Nine Network, Andrew Johns, had passed on to punter Eddie Hayson that the mare could not win.

In a second drama-filled day at the stewards hearing, Hayson said he in fact made his own inquiries after talking to Johns at the football on race eve and was told by an un-named source the vets had been attending More Joyous all week.

After hearing this information, Singleton told a pre-race television interview that More Joyous couldn't win "because the trainer's son says it can't".

In other interviews after the race, in which the mare finished second last, Singleton sacked Waterhouse as his trainer and repeated his claims about her son.

After being charged with conduct prejudicial to the image of racing, Singleton said his behaviour was regrettable.

"My behaviour was absolutely unintentional and regrettable and had unintended consequences," Singleton said.

"This is my first and hopefully last stewards' inquiry."

Chief steward Ray Murrihy said Singleton had been given a discounted penalty - down from $20,000 - taking into account his guilty plea and good character in the racing industry.

Earlier Murrihy told all parties there was to be no repetition of the name calling of last week's hearing and that publication of documents in evidence was contempt on the proceedings.

Last week Gai Waterhouse fired back at Singleton during the inquiry sitting, accusing him of being drunk on the day and a "sham".

Singleton gave his side of the story in a weekend column for Fairfax Media which also published a list of phone calls between several parties that was part of the evidence.

The relationship between Gai Waterhouse and Singleton began to crumble after she selected barrier 11 for More Joyous in last year's Cox Plate against the owner's instructions.

"This started with the barrier draw in Melbourne and my finding out advice Eddie Hayson had received," Singleton said.

"Hearing what Andrew Johns had said was the straw that broke the camel's back between Gai and I."

Waterhouse remained silent for most of the day except to plead not guilty to two charges relating to treatment More Joyous received earlier in the week.

The mare was given an antibiotic as instructed by Singleton's vet who also inspected her before the race and passed her fit to run.

The onus is on Waterhouse as a trainer to report anything that might affect a horse's performance to stewards to enable an independent inspection.

That part of the inquiry was adjourned until next week, and Murrihy said the stewards would also look at evidence about the identity of the second person who gave information to Hayson.

Waterhouse was excused from the inquiry before Singleton's penalty was announced.

As he left Singleton said it was time to move on.

"That was yesterday, let's move on to tomorrow," he said.

"(I feel) good. It's over."

As is his 40 year friendship with Waterhouse.