Well exactly, if they refute they signed it its going to lead to more legal complications and basically what it all boils down to is money i.e. it'll go to the solicitors to sort out and thats a chunk out of the inheritence. Basically it has to be clear cut and above board and this stuff gets messy if it isn't. Mother had to act as executor on a will for a friend who passed away and his former wife's family wasn't covered by the will (passed away before him) but did put money into the house/business and her family they basically chimed in and said wheres our share? Anyway it inevitably went to the solicitors to sort out and that cost a bit they were basically offered a chunk of cash to avoid further legal action and settle the case, which they did. But it would have been better if it had been thought about beforehand.