When one purchases property that contains covenants, the purchase is considered acceptance of the terms of the covenants. HOA CC&Rs are considered a contract. In some states during the process of purchasing, one must sign an acknowledgment that the property is in an HOA and that the covenants and assessments are a contractual obligation. This is becoming more common as the numbers of HOAs rise, and as there is case law developed. However, not having signed such a notice does not mean that you are not party to a contract. Purchasing the property in an HOA or with covenants perfects the contract.
However, not all covenants create an HOA. Often developers attach covenants to the land to provide some uniform conditions for the development: minimum square footage for dwellings, maximum height, disallowing further subdivision, allowable building materials, landscaping, animals, fencing, etc.
Sometimes covenants are perpetual--they never end; other times they self-renew every so many years, usually with an option to modify them during the last year before renewal; sometimes they expire. Typically anyone who resides in the same development can sue to enforce them, and if there is an HOA, the board has the responsibility of enforcing them.
If the covenants expired prior to your purchasing the property, especially since you researched it before your purchase, you have a strong case. The neighbor's case is that that was the covenants when HE purchased. What is decided will depend on the judge, case law and written statute, as well as the specific language in the covenants (yes, I understand they expired, but hte language used is important). I hope your attorney is well versed in real estate law, particularly relating to HOAs and convenants.
No, I am not an attorney. However I am in my 5th year on my HOA board, and the 3rd year as its president. Previously I was on a committee that rewrote our CC&Rs (which passed with upwards of 95% of all homeowners approving them). During my 2nd year on the board I prepared amendments to the CC&Rs and Bylaws, both of which were approved. I am also the person who works with our attorney when we need legal advice. She specializes in real estate and HOA law (representing both sides, depending on the client) and is an adjunct law professor. I regularly keep up to date on HOA laws around the country in general and in my state in specific.
Well written covenants provide protection and structure for all parties. I do not live in a neighborhood with extensive nit picky rules; that is a deliberate choice by the neighborhood. We would not have purchased here if it had been that type of neighborhood.
As to the fence, different states and cities have dfferent laws. Unless he was obligated to share the costs by law or ordinance, while it would be nice if he had been willing, he was not required to.