That fact that he shows BOTH gifs of Chris checking the kicks, proves that the end result of the fight was, in fact a "fluke".
The point where the legs meet is random and you can't really plan for it.
You are hardly even thinking about it. You are just trying to check properly and counter.
Chris got lucky and the legs met in his favor.
Did he intend to break Silva's leg? NO.
His intention was to block the kick, take as little damage as possible and counter. You can even see his "oh shit" face when the kick is launched.
Is the win legitimate?
This should put fighters on notice about low kicks and proper checking technique.
"Empty your mind, be formless, shapeless,... like water" - Bruce Lee
[Yeah, that's right,.. Be like water. Fall on the ground & spread out helplessly.]