Are you really supporting the idea that potential customers of Moz, who go out in search of Moz and stumble on Doz, would confuse the two? Sure, they share two out of three letters, but they don't sound the same (no risk of a misspelling leading to Doz) or look the same.
It doesn't appear at all the that Doz is trying to conflate their brand to cause confusion or imply a relationship.
My guess is a company like Doz doesn't have the resources to fight, but they should. I can't imagine a court agreeing that even a "moron in a hurry" would confuse the two.