The allegation going around Corpus is that it was not a finder's fee, but a kickback. Capelo is a defense attorney and he got the check from a trial lawyer shortly after he settled a large case ($millions as I recall) with that trial lawyer's firm. The allegation is that the trial lawyer paid a $100,000 kickback to get Capelo to talk his client into taking the deal and paying big bucks to the trial lawyer. Now that the story is out and Capelo is never going to be in a position to (allegedly) sell out a big client again, the rest of the trial lawyers in Corpus want him out of the Texas Legislature.
I'm not saying it happened, but that is what the allegation is. This story does a piss poor job of explaining the background.