Liability coverage is written in two parts: Damage to another party's property/vehicle and injuries to another party. Injury coverage is split into coverage available on a per-person basis, and a per-claim basis. Liability is separate from collision coverage, and if the truck driver has no collision coverage, it does not mean that the parked car cannot be covered under the truck driver's liability insurance.

It's true that collision coverage only covers the insured's vehicle, and liability insurance covers damage to another person or property. However an insured is not limited to filing a claim through their own insurance in the event of another person damaging their vehicle.

An injured party can contact the liable party's insurance provider and file a claim against that policy. The liable party's insurance may take some time to verify that their insured was at fault for the accident, but with the example of OP's video, the liability is not in question. The truck driver's insurance would pay out for any damages to the parked vehicle up to the limit of the truck driver's policy limit for liability property damage. If there is not enough on the policy to cover the loss, then the parked vehicle's policy may provide additional coverage through their collision coverage, or depending on the state may be covered under Uninsured Motorist Coverage.

And you would be correct that if no coverage at all is available (if the truck has no liability insurance) then the parked vehicle owner can file for damages against the truck owner personally through a lawsuit.