Property Insurance - can one benifit from a mistake?

[Bob1954]

I live on an estate comprising of leasehold Flats, freehold Houses and shared private roads. The managing agents only insured the Flats for building cover and seemingly failed to insure the roads, gates and street lights for Damage. The gates were damaged by a hit and run driver two years ago and our insurers agreed to pay for repairs as they believed the gates were included in the Building Insurance for the Flats under the the definition of "communal area". Residents were relieved and the gates were repaired and we just paid the policy excess. The managing agent has recently tried to make us purchase "Engineering Insurance" for the gates which pays him a high commission. The Directors have requested sight of our insurance documents as we felt from past experience we were already insured for the gates. The policy documents revealed Building insurance in place for the Flats but no Damage insurance for the shared roads. The Directors feel this was probably an unusual configuration to have both Houses and Flats sharing the same private roads and the insurers did not understand what the insurance risk comprised of. It is obvious to the Directors we were not fully insured and have instructed full cover to be put in place. The Managing agent is now blaming the Directors for the underinsurance error although the Agent was employed to manage our insurance, repairs etc. Furthermore when challenged to return the monies for the gate repair to the insurers they are refusing and arguing as the Flats paid for the insurance then the Flats they should be given the Houses proportion of the gate repair costs! Strange as this sounds, there is an element of logic as the Houses have as a consequence of not paying these insurance premiums for 15 years in their service charge have saved some money. But the counter argument is the Flats have paid the correct premium and it is unfair to receive a windfall payment now. Sides are been drawn and the Flats like the idea of a windfall and the Houses are annoyed at the prospect of loosing a big chunk of their sinking funds. There is some sense in sharing the insurance windfall between all properties but should this be returned to the insurer? The Managing Agents are cleverly dividing the residents to avoid blame. Any advice please?