The wheelchair-bound man faced trial in the Supreme Court accused of shooting his alleged victim at Littlehampton, in the Adelaide Hills, in October 2017.

The court heard the 26-year-old retaliated by attacking him with an axe, rendering him paralysed from the neck down.

It took a jury of six men and six women three hours to reach its verdict on Friday afternoon.

Outside court, defence counsel Stephen Ey said it had been a "long and harrowing journey" for the acquitted man and his family.

"This is only round one," he said.

"We've got to try and recover some compensation for (the man) and what he's had to suffer.

"It shows on the emotion on everyone's faces in court today ... it's been trying for everyone."

During the trial, jurors heard the 32-year-old accused man's ex-partner told him in June 2017 she wanted to separate and her new sexual relationship had begun by August.

Prosecutor Lucy Boord said he had just returned his children after an access visit when he asked the other man to view his gun collection.

Once inside the garage, Ms Boord said, the accused took a rifle from the safe and pointed it at his victim's stomach.

"He at that point realised something was very, very wrong," she said.

Ms Boord said the accused shot the man in the abdomen and told him "this was no accident, that he intended to kill".

"(The shot man) had to escape or fight back," she said.

The court heard the injured man pulled himself up and grabbed a nearby axe before striking his attacker's head several times.

But defence counsel Marie Shaw said in her closing remarks this week the alleged victim's account was undermined by forensic evidence.

"He is not telling you the truth about where he was shot," she said. "He's not telling you the truth about how he was shot."

Ms Shaw said the injuries on the accused man's neck could not have been inflicted while lying down, as the victim told the jury.

"He has to be covering up that this is not self-defence when he strikes my client repeatedly in the neck," she said.

"He must have been standing over my client to ram that axe into my client's neck eight times in a very localised area."

The court also heard the ex-partner met another woman after the shooting and the pair lived together briefly at the Littlehampton home.

The ex-partner denied they were ever in a relationship and that they discussed suffocating the tetraplegic man, though Ms Shaw told the court the other woman was spotted at the accused man's rehabilitation centre on New Year's Day 2018.

The names of those involved in the case have been suppressed.

Australian Associated Press