Another spin on this: Most trailers and items are covered by your car insurance if it was attached to the tow vehicle, If the police report doesn't mention attached to tow vehicle you can always say it was.

Some Insurance it doesn't matter if attached or not as long as it is the tow vehicle.

Another possibility, is because it was a hit and run ( and the police report says so, right?). There may not be a deductible, some policies waive the deductible for hit and runs. It's worth asking at least.

True, in certain instances, about the hit and run deductibles, but only if you have comprehensive coverage on your vehicle.

Its kinda of tricky because you could of filed a claim with your auto insurance if it was hooked up to the tow vehicle, but even if he had home owners or renters insurance it might not of covered the damaged sinced it was parked on the street and not on the property. Thats why its very important to read and understand your policy, sometime the cheapest isnt the best policy.
I have a friend who keeps his boat and trailer in front of his house on the street, he's fortunate enough to have an old 2nd truck that he leaves hooked up to the trailer just for this reason.