I agree with trisher that the crux is that the incident, assault, whatever you want to call it, is recorded.
It's not a judgement on the patient, or used to instigate proceedings, but simply to put into context the task that the healthcare worker was trying to do.
Nurses, doctors, dentists, physios etc all have standards to meet.
Anything that compromises those standards should be recorded, to protect the professional standing of the HCW.
For example, a patient with dementia might well decide they don't want to take their medication, and hit out at the HCW trying to administer it.
Unless this is recorded, it would be assumed that the HCW wasn't doing their job properly and was failing to ensure the medication had been taken.
I agree with jane10 I'm afraid Kitty, that by not recording these incidents your DH is making things more difficult for anyone who takes over the care of his patients, because they're not getting a full picture of how cooperative or otherwise the patient might be