The font that Hank's "Bass Pro Shops" hat is written in is alternately red/black between shots.
When Dale comes around the corner in the bad neighborhood to buy "bait" with Hank, for the first frame, he has gray hair.
It is revealed in the series finale that Boomhauer is a Texas Ranger. When Hank handed him the "bait" he should have been able to quickly identify that as crack cocaine.