Instead of easing out gradually and allowing forward motion to ease him from the pocket, Chui angled out almost at right angles and seriously squeezed up Ponderosa Miss, who was charging through a gap from last in the field.
Ponderosa Miss was pushed on to the heels of the horse directly ahead, whose hind legs struck her head, causing damage.
Chief stipendiary steward Ross Neal recommended to the JCA judicial panel that penalty considerations should begin at one month.
"We have a standard at the moment that one month is the absolute minimum when interference causes a rider to be dislodged," Neal told the Herald yesterday.
"Then you add in aggravating factors, which in this case is career- threatening injuries to the horse, which is hugely significant.
"However, the judicial panel decided to go with just the one month."
There is no top-end penalty clause for such serious cases of interference and no one would have been surprised if Chui had copped six months.
"Maybe the panel took into account his frank guilty plea," said Neal.
But how significant in terms of penalty can a guilty plea be counted when the actions are so blatant there is absolutely no defence? It cannot be counted.
Peter Hollinshead told the Herald the interference is the worst he's seen in 50 years in racing.
"That boy had to see our mare coming through the gap he closed so suddenly. On the replay you can see him turn his head and look at her."
Hollinshead said one of the large syndicate of owners has told him if Ponderosa Miss cannot be saved he will look to take legal action to sue Chui in the courts for the mare's considerable value, conservatively estimated at $750,000 to $800,000.
Personal injury cases cannot be brought to court in New Zealand because Accident Compensation takes care of that, but loss of personal property is entirely different.
There are precedents. Malcolm Johnston, resident comedian on the hugely popular Off The Rails Australian television programme, was fined A$120,000 during his riding days when he badly injured a fellow jockey's back and killed the horse he was riding.
In Hong Kong, Australian jockey Chris Munce was jailed for flaunting Hong Kong Jockey Club rules.
"I'm not sure where New Zealand racing stands in terms of taking racing matters to common law, perhaps we need to find out," said Neal.
Chui was Hong Kong's champion apprentice in 2008, riding 83 winners before moving to Perth, where he rode 65 winners in 2 seasons before arriving in New Zealand this year.
Ponderosa Miss is New Zealand's most prominent emerging racemare. Her last-to-first wins at Ellerslie and Te Rapa before Saturday were stunning. The owners were offered $350,000 after her second race start when she came from last into third at Ellerslie. "But she is owned by a syndicate and can't be sold," says Hollinshead.
"She would have buried them yesterday if she hadn't been checked.
"Daniel Hain was in tears. He said they wouldn't have seen which way she'd gone."
If Ponderosa pulls through and infection does not settle into any of the 25 metal clips holding the side of her head intact, the worry will be whether or not she has lost confidence when put in a race.
"I'm actually not worried about that," said Hollinshead.
"She is the quietest filly I've seen and I don't think she will worry too much if she survives."
In the previous race, Chui came from last to burst past a talented field and win the Guineas Prelude on Nigelissima's stablemate Stratocaster, prepared by Emma-Lee and David Browne.
On a day when on-pace runners were favoured it was a remarkable performance.
Stratocaster is a magnificent type of early 3-year-old and looks destined for a high ranking.
He had only one previous start leading into Saturday when he came from a long way back to finish close up after racing greenly early.
The favourite Turn Me Loose was not disappointing in finishing second.
