The Houston Chronicle has an article: "Even bugs can be Parrotheads" (by Ken Hoffman)
It took me awhile, but I’ve found out why Jimmy Buffett was coughing and hocking up loogies during his concert at Minute Maid Park …
That’s what happened. Buffett swallowed a bug right before the concert. The roof was open and something was flying around. Gulp! The little bugger stuck in his throat.
The bug didn’t affect his singing, but after each song Buffett turned from the microphone, hacked pretty hard and looked like he was searching for a spittoon.
I’m told he finally coughed up the bug midway through the second half of the show, and the concert continued without incident.