Accidental, but no loss to society.
For those who claim excessive force, people can become almost superhuman when it becomes apparent to them that they're about to lose their liberty.
I was once in a custody suite with a suspect. Getting booked in, everything going fine until he was asked to remove his jewellery.
He went absolutely Radio Rental, started kicking, punching, biting, spitting, screaming etc. It took 6 of us to restrain him and prevent him from head butting the floor.
It turned out he liked to work on his physique and had a fit of 'roid rage'.
In extremis, some will act and behave as befits their situation.