"There wasn't real trouble ... [but] the place was filled with people in their 40s and 50s staggering around and trying to relive their youth. It wasn't pretty.
"When they closed the bar, it was like a braying mob, angry that they couldn't get another drink. It looked like it was going to get nasty, but fortunately it seemed to calm down without any serious problems."
Another concert-goer said he saw a small group "became unruly and aggressive" but thought it was an over-reaction to close the bar.
Police told him there had been a couple of fights and some drunken behaviour and they were worried the disorder might spread.
"I took a long walk among the crowd at that time. They were all in a relaxed, happy mood enjoying the atmosphere and the music. There was absolutely no evidence of out-of control behaviour," the man said.
"I would add that I was not personally wanting to purchase any further alcohol, but I felt strongly that the rights of other people were unreasonably interfered with by some meddlesome busy-body who had authority beyond their competence."
Villa Maria director Fabian Yukich said 99 per cent of the crowd behaved themselves and had a good time.
"It was a long day ... and a very, very hot day and after consulting with the District Licensing Authority and the police, we decided to close the bar a little bit early - which was probably a good decision. The call was made that if we closed it now, we wouldn't end up with issues later. It was more about being proactive, rather than acting afterwards."
A few concert-goers became disgruntled when they found the bar closed, Mr Yukich said, "but once we explained to them the reasons for closing the bar they understood".
Villa Maria had hosted 20 concerts and organisers always "tried to make it an experience people will enjoy".
"There may have been a couple of people who had had a little bit too much to drink ... but you try and stop that sort of thing from being too bad."
Mr Yukich said the winery normally closed the bar about 8.15pm but one of the problems on Saturday night was that it was before the final act, the Exponents, played.
Auckland Council spokeswoman Angela Jones said it was Villa Maria's decision to close the bar but licensing authority representatives at the winery were consulted.