I'm curious as to the longer effects:
On the tax lawyer site I'm trying some of search terms and not getting a map. for others I do.
I haven't researched it. For something like this my gut is a panda type of penalty. One reason is that there are some heavyweight firms on that list and they get links, plenty of them. Of one I saw, Caplan and Drysdale is a large firm. They could get tons of links...and yet they were about 6 or so on one of the search terms. If a far smaller firm is way above them...it suggests a lot of work on the local side, possible total concentration on tax as opposed to widespread law practice and/or a lot of links that expose some of the things google is cracking down on now ie too much anchor text, too many simple crappy links.
I haven't looked into it...but that is gut...and experience based on seeing drops in the pac for sites with some of those type links.