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.