I think thats the end of the line for Castillo.
I felt it was more his inability to engage than Montiels ability to fight that served as the basis for this result.

Although admittedly, I'm not a fan of Montiel, from a neutral point of view
I din't think he did anything spectacular and he certainly didn't live up to the performancees with which the commentators were comparing the fight (Lacy Calzaghe Hopkins Tarver.)