It's not too much of a stretch to imagine the events detailed in this thread -
https://www.arrse.co.uk/community/threads/an-odd-occurrence-this-week.303421/unread (as an example only) resulting in something being passed on - and recorded - as an incident, because there was a copper at the ER waiting to take someone else's statement, say, then filed (ostensibly) as NFA.
Fast forward a couple of years to the subject recorded in the (non) incident moving on to a new relationship and someone deciding under the auspices of the Domestic Violence Disclosure Scheme to warn the new partner of the report of the subject's involvement in a suspected DV incident.
Cheers, hypothetical Plod. We can all sleep safer in our hypothetical beds.