It was certainly a dirty fight from Chavez, not sure I agree that Rios would have stopped him. Either way Rios is not big, fast or skilled enough to beat Brook.
What is Chaves then? Chaves was even an amateur welterweight before turning pro. Rios was manhandling Chaves on the inside. Chaves had to resort to gouging out Rios' eyes to keep him off when he knew he couldn't win the fight on the inside.
I disagree Chaves is a rough customer that's what he does. Rios had problems with Chaves and couldn't put him away or impose his will on him that fight was up for grabs when the DQ occured. Thurman got rid of Chaves after a shaky few rounds like a champ. I thought Bradley beat him but Chaves got the draw.