With celebrity chef Maggie Beer appearing as a character witness, the District Court in Adelaide has been urged to impose a suspended sentence on Trevor David Jones after hearing of the family breakdown and his slide into depression which sparked his offending.

In February 2015, Jones went Kellermeister Wines at Lyndoch and opened valves to drain wine worth almost $300,000 from four of the company’s tanks.

He pleaded guilty to two counts of property damage and in sentencing on Monday, defence counsel Mark Griffin detailed the issues which led him to take “foolish retribution” against a company that was previously owned by his father and where he had been a winemaker.

Mr Griffin said Jones had suffered from depression for some years and bad blood between him and his father led to Jones being fired in 2010 and also cut out of his father’s will after the sale of Kellermeister in 2013.

“Every person has his breaking point and Mr Jones must have reached his that night,” his counsel said.

“But it was not a solo act, borne out of nothing but just some nasty performance.

“it was an act that was serious and wrong but it had its origins in deep feelings of betrayal and treachery and the belief, rightly or wrongly, that he had become a worthless individual.”

Ms Beer, who worked with Jones to make products for her own business, told the court the 60-year-old had a “generosity of spirit” and she only had feelings of support and understanding for him.

“He certainly never let me down on any occasion,” Ms Beer said.

Outside court, she said her friend’s actions were “absolutely out of character”.

“Who knows what goes on in a person’s head when they’re struggling,” she said.

“As a friend I never want to see Trevor without giving him a big hug.”

But in his victim impact support statement the current owner of Kellermeister Wines, Mark Pearce, told the court that what Jones did was an act of “sabotage” that had caused both direct and reputational damage.

He said the winery had lost up to $600,000 in contract business since the incident, with other wine producers reluctant to use its services.

“The crimes of Trevor Jones were calculated to cause damage and they did just that,” Mr Pearce said.

He said Jones had engaged in a campaign of denial and smear against him, adding to the impact of his crimes.

“By denying the charges and deliberately casting innuendo in the way he did, Trevor Jones inflicted irreparable damage to my reputation,” Mr Pearce said.

Judge Jane Schammer will sentence Jones in November.

AAP