A man who was injured in the grounds of a stately home after taking his grandson on a bat walk told a nurse he had been stupid to have taken the route he did, a court heard.

John Cowan told the nurse he had been wanting to get the child home because he was tired, it was claimed.

Mr Cowan, 65, a former water quality manager, suffered a fractured ankle and underwent a series of operations following the incident at Hopetoun House, on the outskirts of Edinburgh, on September 5, 2008.

He said he "stepped off" a ha-ha – a sunken feature which can be found on country estates – as he made his way back to the car park with his five-year-old grandson Ross.

Carol Terry, 41, a sister with the Scottish National Blood Transfusion Service, who also runs a bat hospital in her spare time, had also been at the event in the grounds of the house and went to help after the incident.

Mrs Terry said: "He said that he could not believe he had been that stupid when he had been told not to walk that way.

"He had reached the ha-ha and knew it was there and could have walked round.

Mr Cowan wanted to get the child home because he was tired and jumped from the ha-ha, the witness said.

Mrs Terry added: "He said he did not think it was as high as it was."

Mr Cowan raised an action suing the Hopetoun House Preservation Trust and its trustees, including the Marquess of Linlithgow and Lord Hopetoun at the Court of Session in Edinburgh.

Damages in the compensation claim have been agreed at £35,000, with liability contested.

In the action it is claimed they became disorientated in the darkness.

He said it was pitch black at the point where he went into the ha-ha and thought there was a lawn and path in front of him.

The judge, Lord Bracadale, will give a decision in the case later.