Escape from Party Island - S3-E17
Continuity mistake: Before Hank & the old ladies depart Arlen, the guys (Bill, Dale and Boomhauer) are in the alley behind the van. The next shot they are against the wall and the van is opposite them in the alley.
Escape from Party Island - S3-E17
Continuity mistake: As Hank is driving, whilst trying to get off the island, a large Alamo beer display can drops in front of the van. In the next exterior shot you can see it actually drops again but to the left of the van.
Escape from Party Island - S3-E17
Continuity mistake: In the scene where Peggy is singing and Bill joins in, you can see his white singlet is clean. In the following shot of Bill it has a number of stains on it.
Answer: Jeffrey Boomhauer is a Texas Ranger as can be seen in the final episode at the end when he sets his wallet down, it flips open revealing a Texas Ranger badge.