It happens, and it is a fact question rather than the end of the claim. What matters is that most of the proof does not depend on the owner agreeing.
What establishes identification
The animal services file. This is the strongest route, and the reason to report promptly. An investigation records the address, the animal, and the owner’s details independently of anyone’s account.
Rabies and vaccination records. After a bite a dog is typically subject to observation or quarantine, which generates dated records tying a specific animal to a specific incident.
Witnesses. Neighbours who know the dog, delivery drivers on that route, anyone who stopped to help. A dated statement in their own words is worth a great deal. A template for taking one.
Camera footage. Doorbell cameras, business security cameras, dashcams. This is the most time-critical item on the page — most systems overwrite within days, so a request has to be made almost immediately.
Prior complaints. A dog with a history at that address is much harder to disown.
Physical evidence. Photographs of the dog, the property, the gate. Torn clothing.
Why owners deny it
Not always dishonesty. Sometimes the dog genuinely belongs to a tenant, a relative, or a visitor, and the person you spoke to is not the owner — which matters, because § 767.04 makes the owner liable, and identifying the right person is part of the claim.
Sometimes it is an insurance reflex: a denial buys time and shifts the burden.
What to do now
Report it today if you have not. Every route above runs through a dated official record, and animal services files close and get purged.
Request footage in writing, immediately. Name the date and time window. A polite written request preserves it; a phone call often does not.
Write down everything you remember about the dog — size, colour, coat, markings, and where it went afterwards.
Do not confront the owner again. Identification is established through records and witnesses, and a further exchange usually produces nothing useful and occasionally produces something harmful.
If the dog cannot be identified at all, that is a different and harder situation.