Zenimax, you really need to offer free, full respecs whenever you put out a patch that includes skill balances. Nerfs to even one skill could cause an entire build to no longer be valid. You already refund points put into a skill that is nerfed, so you understand that compensation is necessary, but simply compensating one skill is a meaningless gesture when a player has to pay for a full respec anyway.
This is pretty much an industry standard. I'm sure you've seen it in other game's patch notes: there's always something like "due to the following changes, Warriors have had all of their skill points reset" or something similar.
It could be as simple as "the next visit to a Shrine of Stendarr within X days of a patch is free," or you could mail each player a Token of Stendarr that can be redeemed at a shrine but have it expire in X days.