Should he take compensation from the insurance company in full or only as much as he paid?
The view favoured by this website is that commercial insurance of all types is haraam, and that the one who deals with it should not take more than what he paid.
With regard to the one who has been harmed by loss of life or property and is owed diyah, he has the right to ask for it to be paid in full, whether it is given by the other party himself or through the insurance company, because the one who is entitled to diyah or compensation has a right and he is not responsible for the other party's dealings with the insurance company.
The first party -- who is the one who is insured by the insurance company -- is dealing with a haraam contract, and the second party -- the one who has been harmed -- does not have a contract with the insurance company, rather he has rights over the one who is dealing with the insurance company.
See also the following fatwas: 8889, 70318, 125801, 103233.
And Allah knows best.