Insurance is a must. It costs little and should be compulsory. The ONLY way it can be confirmed or vetted is for the BMFA to issue an ID card that MUST be worn as a badge (NOT around the neck for obvious reasons) when, in effect, all members vet each other. All model flying sites are usually run under the auspices of a local club and they would, I am sure, be happy to monitor it.
A life or an injury to person or property can be VERY expensive and way outside one's normal bank balance, so it is essential. Particularly in this case.
Whether THT would arrange for it I rather have my doubts - quite a few in fact. Still, it is up to him to state OW position.