Horrible ending (SPOILER ALERT!)

So this rancher's pretty blonde sister runs away to the big city, gets raped by some thugs, and then sold into sexual-slavery. She ends up working as a high-priced call girl because she's exceptionally fresh & pretty, but then one of the guys she's supposed to "entertain" one night turns out to be a sadist who beats the crap out of her, so badly that she dies, got it? Well, when her rancher-brother comes looking for her, he blunders his way around to killing all of the bad guys, EXCEPT the guy who beat her to death! Seriously? The one guy you MOST want to see him kill gets off scot-free? WTF?!!