McDonald was given a discount for his guilty plea and co-operation with stewards.
But McDonald's lawyer Bret Walker argued a six-to-nine month suspension would be more appropriate considering 25-year-old McDonald's "extreme youth".
If his ban is reduced to a suspension, McDonald's legal team said the top jockey would volunteer to help with apprentice schools to educate younger jockeys.
However, Racing NSW chief steward Marc Van Gestel hinted McDonald could be considered fortunate to receive the six-month reduction because the special circumstance rule in question states the person must plead guilty as well as co-operate with stewards during the investigation.
Van Gestel said McDonald repeatedly denied having an interest in the bet before an admission of guilt in an interview with stewards in November last year.
When quizzed about the bet in the initial interview with stewards, Van Gestel read a transcript whereby McDonald's comments included:
"You can go through my whole phone, I've done nothing wrong. I don't bet. It would just be like any Joe Blow in the street coming up to me and saying 'what's your best [ride] today'."
He was then quizzed on whether he knew who Gardiner bet with and how much.
"No, I don't want to know, I have a hard enough job as it is."
The inquiry had been adjourned with the appeals panel likely to deliver their verdict later this week.