Thomas Orchard, 32, died in October 2012 after being arrested in Exeter.
But Bristol Crown Court heard custody sergeant Jan Kingshott, 44, "did his best" despite the outcome.
Mr Kingshott and civilian detention officers Simon Tansley, 38, and Michael Marsden, 55, all deny manslaughter.
Patrick Gibbs, for the defence, said: "What Mr Kingshott did was straightforward and professional and, in almost every respect, standard procedure.
"You will not find any anger, any sudden movement or over-reaction at Mr Orchard's behaviour, or any brutality.
"What you will find is force. We need to be straight with ourselves about the practical realities of force."
Mr Gibbs described Mr Orchard - who had schizophrenia - as "angry and aggressive" when he arrived at the custody centre.
Mr Gibbs said: "It was not Mr Orchard's fault that he was behaving the way he was behaving. Mr Orchard was not at fault but it doesn't mean force was unnecessary.
"It was not obviously unnecessary to look to the equipment which they had been given and had been trained to use."
Church caretaker Mr Orchard was handcuffed, held down and had an emergency response belt put across his face to restrain him, the court previously heard.
Mr Gibbs said: "Mr Kingshott does not pretend that everything was perfect or there is nothing that could have been improved.
"But he is not a computer. What he did not know was how this would turn out."
He told the court Mr Kingshott "did his best" and "he was a good custody sergeant, a decent person and a good witness".
Mr Orchard was pronounced dead seven days after the incident in hospital.
The trial continues.
A custody sergeant who dealt with a man who died after having a heart attack in a police cell followed procedures "in almost every respect", a court has heard.