Hey there. I believe the song generally mixed up is entitled "The Asshole Song" and yes I'm pretty sure it's by DAC. "The Lawyer and the Asshole" is actually the title of one of Buffett's songs that he wrote during a time when he wasn't allowed to play "God's Own Drunk". "Lawyer" has since disappeared since the '80s, so I think "God's Own Drunk" is allowed to be played again... unfortunately, Buffett's only played it on a handful of occasions in the last 30 years.

You are right on with the common misconceptions. Here are the lyrics to The Lawyer...
I recall sitting about 5th row at this show singing the refrain at the top of my lungs...
Prince Buckley was a real Pr!ck...
Cheers

Here are the lyrics to the song:

"The Lawyer and the A$$hole" - by Jimmy Buffett

This lawyer and this a$$hole
Out in California
Told me I can't play "God's Own Drunk" for you no more
I hate bein' told
What I can and can't do

So here's a little message
'Till I can even up the score:

Kiss my ass, Mr. Greedy
Somethin' here is wrong
You want all that money
And you never wrote the song

I bet your poor daddy's
Rollin' over in the ground
So I'll just sing my own good tunes
They still get me around

Kiss my a$$
Kiss my a$$
Kiss my a$$