The biggest surprise came when a few friends in the know brought appropriate attire so the couple could dress up, and within minutes of the proposal, they were standing in front of a celebrant who had been standing inconspicuously in the corner - and they tied the knot.
Mrs Herd-Tily, 53, said she changed her mind about marriage for sentimental reasons.
"Things have happened recently. As you get older, you kind of realise that companionship and love are important.
"I work at the hospital and you see people every day and how sick they are, and just how people don't have people visiting. It's very sad.
"It makes you become a bit more aware of things like that. At the end of the day, you may not have anybody. It was a home truth."
Mrs Herd-Tily said she had been planning the event for months. Mr Tily, 47, said he got "a hell of a surprise" when she popped the question on Saturday.
He said he suspected something was up when he arrived at the club and saw a few "professional-looking" people he didn't recognise.
Mr Tily said the wedding had made his year. "I've been wanting this for a long time," he said.
"I've had a smile on my face ever since."
At the end of the night, Mrs Herd-Tily said her new husband failed to carry her across the threshold.
"We're both too old for that," she said. "He just bought me a beer and said good luck."
The Dunedin couple are planning a honeymoon to Melbourne and the Gold Coast later this year.