I don't think the insurance would pay anyway as the damage was as an act of public unrest or civil disorder so wouldn't be covered (even if the policy had been fully comp, which it wasn't)
No disrespect but are you sure? It is quite difficult to buy third party motor insurance and even if you do it costs MORE than Fully Comp. I doubt that vehicle could have been operated legally with minors on board, without fully comprehensive insurance and this is not an act of civil unrest it is arson, which is covered.
If the vehicle is correctly insured the insurance will pay out, no question. If it is not, then somebody is for the high jump