Parishioners from Holy Trinity Church also became "unpleasantly ill" and three of those attending only escaped because they were vegetarians, according to the Guardian.
Croucher, 40, who said he has worked in hospitality for 20 years, fronted court earlier this week.
He was sentenced to four months in jail but won't spend time behind bars with his sentence suspended for 12 months after he admitted the charge of contravening food regulations.
"I hate to say it, I really hate to say it, but I think I was rushed. I was rushing," he said.
Croucher, who no longer works at the pub, said the "horrible circumstance" has made him "a better chef".
"Remorse is an understatement. This is something I will never forget. Because of it, I am a better chef and it is just a shame the cost of it had to be what it was."
According to Judge Sarah Campbell, who presided over the case, the meat wasn't handled correctly.
"The mince was not cooked properly and was placed into a pan with iced water. Croucher needed to leave, so put the mince in cling film and put it in the fridge overnight," she said.
"Having left it, he cooked it again and added warm mashed potato. He did not take the temperature when it was served."
While church members didn't want retribution against the pub, Croucher or its landlord, the judge cited "evidence", adding the incident was not a "one-off mistake".
"The pub should have been taking steps to be improving. Inspections in 2015 gave it three stars and in 2017 gave it only a one-star," Campbell said.
However, since then its rating has increased with a maximum score of five stars on hygiene, according to Newsweek.
In the case of the contaminated shepherd's pie, the Guardian reported the pub owner admitted to three charges of contravening food regulations and was fined $17,500 and ordered to pay $1900 in court costs. His company was also fined almost $5,800.