On the day of the incident, PC Harrison was among a team of convoy motorbike outriders escorting the Duchess of Edinburgh as she left the Foreign and Commonwealth Development Office in King Charles Street, just after 15:00BST, jurors were told.
The car that the duchess was in and a police back-up vehicle were part of the convoy.
The defendant, who had 21 years of experience in the specialist escort group, said he “couldn’t put it into numbers” how many times he had undertaken the journey and that he was “very familiar” with the route.
Mrs Holland was 2.9m on to the crossing when PC Harrison’s motorbike hit her, the court heard.
She suffered a skull fracture, bruising to her arms, legs and body, as well as fractures to her lower legs.
A post-mortem examination gave the cause of death as complications from a severe head injury.
PC Harrison, who became emotional while giving evidence during the trial, told jurors that the collision was a “tragic accident” which occurred in circumstances he had “no control over”.
Under cross-examination, he accepted he forgot to switch on his body-worn camera and did not use his whistle as he approached the pedestrian crossing but insisted he had not been complacent that day.
“She was just there in front of me,” he told jurors.
“She just appeared, between the kerb line and the point of collision.
“At no point did I see her on the island, I’m sorry.”
