Its funny to see Moz employee defending their company. This is HN. Most people here is highly opinionated and most has made up their mind. Nothing you say can ever justify what your company did.
Just do what Opera did and take back your lawyer letter. Don't make this mess any bigger and you'd do fine. If you want, you can prove that Moz can do SEO better than Doz.
SEO is irrelevant these days though. Product is what matters