Vandyke escaped suspension after fronting stewards over a positive one of his former runners, two-year-old Queen Tara, returned to Ipratropium after she ran second when on debut in a Wyong maiden on April 30.

The horse was based at the Randwick stables of Segenhoe Stud, where Vandyke was formerly listed as the official trainer while managing his own Warwick Farm-based team.

The inquiry heard Vandyke had been involved in what chief steward Ray Murrihy had described as a "photo finish" in a similar case when stable star Arabian Gold came close to exceeding the Ipratropium threshold in her Golden Pendant win in September last year.

Vandyke made undertakings to seek the official veterinary advice of Racing NSW senior vet Craig Suann over withdrawal times for the drug in the future after the "close scrutiny" of the Arabian Gold case.

An official notice to trainers warning about the delay in Ipratropium subsiding in a horse's system was posted on the Racing NSW website on October 29 last year and members of the Equine Veterinarians Australia were also sent a newsletter containing the information.

Vandyke also fired off an email on the same day to Segenhoe employees Peter Robl and Des Fisher asking Atrovent, which is a prescribed veterinary medication and causes Ipratropium to be found in horses, not to be used less than five days before any official engagement.

He reaffirmed the withdrawal time in a similar email on February 20 this year.

But after the Segenhoe horses switched to a nebuliser rather than a puffer to receive Atrovent in March, Fisher sought veterinary advice on two separate occasions from the Randwick Equine Clinic about the swab holding time without communicating with Vandyke.

Dr Rachel Sulz then consulted a senior colleague at the clinic and mistakenly advised a 48-hour withdrawal period was sufficient.

Robl and Fisher allowed an extra day and Fisher, who famously was the strapper of Melbourne Cup winner Fiorente, administered Atrovent to Queen Tara on April 27 – three days before she was due to race.

Sulz said Randwick Equine Clinic staff had failed to see the information warning about Atrovent's withdrawal time last year, a mistake Murrihy described as "fairly alarming".

"That was an oversight on our behalf," Sulz said. "This is not an excuse, [but] one of the partners was responsible [for amending swab holding times] and around this time he got kicked [by a horse] and was off work for a few months.

"It was certainly our responsibility and we should have ensured it didn't happen."

Vandyke, who visited the Randwick base only two mornings a week, admitted his time management was "poor" during the period and a "lack of professionalism" had contributed to the breach, which could have been picked up in a treatment record column on daily work sheets Robl emailed to the head trainer.

Some of them indicated Atrovent was again being administered on Segenhoe horses within Vandyke's strict five-day withdrawal time edict despite previous warnings.

Murrihy said stable records indicated both Queen Tara and Aussies Love Sport had been given the drug three days out from barrier trial engagements, which Vandyke had missed, prior to the filly's positive swab on debut.

Vandyke admitted he had told Segenhoe boss Kevin Maloney after the Arabian Gold scare he intended quitting the two-track role at the end of the season. Randwick trainer John Sargent is now in control of the Segenhoe team.

Queen Tara was disqualified from the Wyong race and the placings amended.

Vandyke has indicated he will not appeal the fine.