Indian-origin doctor Jayant Patel, who is facing a manslaughter trial in Brisbane, on Wednesday took the witness stand and testified in the Supreme Court.
According to ABC report, it is the first time that 62-year-old Patel has testified in defence of the charges.
Bundaberg Base Hospital director of surgery has pleaded not guilty to the manslaughter of Mervyn Morris, who died three weeks later at the hospital in 2003.
Patel is accused of criminal negligence for mis-diagnosing Morris' rectal bleeding as diverticulitis and then operating on him despite his age and pre-existing health conditions that made surgery especially risky.
The doctor told the court that he remembered Morris as a very pleasant, honourable man, who never complained of anything, and said it was hard to forget someone with such unusual complications.
Earlier, Ken Fleming opened the defence case, telling the jury it was Patel's reasonable and honest opinion that the surgery on Morris was necessary, and that he was fit to undergo it.
Fleming added that doctors' opinions differ and sometimes despite the best efforts of a surgical team, patients unfortunately die.