The third-term councillor yesterday apologised following claims he shouted and swore at council chief executive Dr Sue Bidrose on Monday during an angry tirade in a Municipal Chambers hallway.
Cr Vandervis initially downplayed the incident as ''just a shot over the bows'', but yesterday said he now accepted his outburst may have been louder than he first thought.
It was also ''possible, but ... incredibly unlikely'' he swore at Dr Bidrose, despite earlier denials, Cr Vandervis said.
''I have no memory of swearing, and it's very unlike me to swear in the company of ladies.''
Despite that, he apologised ''unreservedly'' to those who thought his actions were ''too loud or inappropriate''.
''If I've overstepped the loudness volume by any number of notches, then I do apologise. I do have a fairly loud voice.''
Cr Vandervis repeated the apology in an email to Dr Bidrose, council staff and councillors, saying if he had been ''too loud or inappropriate, I unreservedly apologise to those who thought so''.
His comments came after Cr Kate Wilson earlier this week indicated she planned to file a code of conduct complaint against Cr Vandervis.
Mayor Dave Cull said at the time several councillors had expressed ''considerable concern'' at Cr Vandervis' behaviour, which was said to have included ''shouting, abuse and swearing'' aimed at Dr Bidrose.
Cr Wilson confirmed when contacted late yesterday she had filed the complaint, despite Cr Vandervis' email.
''I didn't read an apology,'' she said.
Mr Cull declined to comment to avoid prejudicing the formal process that could follow.
Monday's incident was the latest in a series of outbursts and verbal altercations involving Cr Vandervis, who has been the subject of numerous code of conduct complaints since first elected in 2004.
That included being banned from speaking to all but the most senior council staff for 15 months, from mid-2011.
The ban came after Cr Vandervis sent an angry email to council staff, ordering them to ''call the DCC dogs off'' and stop parking wardens from ticketing snowbound vehicles after a winter storm.
However, Cr Vandervis told the Otago Daily Times yesterday that despite his continuing frustrations with council processes, he did not have an anger problem and came from ''a very calm place''.
''I've got a farm I can go out to and play with my chainsaws and get rid of any testosterone that might be excess to requirements out there.''
He accepted his tone upset people and led to complaints, but insisted his outbursts came only after more measured approaches failed to deliver results.
''I accept a lot of people don't like my tone. The thing is ... I do make the same arguments without aggression.
''I make them first in emails, then I make them after that quietly, verbally, and then, if there's still no recognition of what's going on, sometimes you just have to raise the ante a bit.''
Cr Vandervis said Monday's incident was the culmination of a year of frustration, but it remained ''inappropriate to be shouting loudly enough for people in the next room to hear''.
In future, his complaints to council staff would be made by email, text message or in a recorded meeting, ''in order that staff don't have to worry that I'm going to be shouting complaints at them'', he said.
But, despite the conciliatory tone, Cr Vandervis bristled at any suggestion he was a bully and denied his apology aimed to defuse a formal complaint from Cr Wilson.
''I couldn't give a tinker's cuss what Kate Wilson does, quite frankly. I gave up talking to Kate Wilson quite a long time ago - I'm only going to live probably another 20 or 30 years, if you know what I mean.''
