Nong O's middle kick - What's the secret ?

Just watched all his ONE FC fights. What impresses me is how he is able to bruise his opponents so deep, leaving some of his opponents with marks behind their armpit !

When taught how to middle kick, I've been told to either :

- land the kick on the arm

- or land the kick on the small zone between the elbow point and the hip bone (mostly at boxing range) with an horizontal trajectory, below the ribs

As such, I only go for the liver / ribs when the opponent clears the path by throwing a cross.

However, Nong O seems to be able to sneak kicks between the arms and the body, sometimes reaching as high as the armpit, and kick in a diagonal fashion.

So the question is, how is he able to not shatter his shin / tibialis anterior on the elbow ? How are his kicks so rarely blocked ? Is it incredible speed ? Is it angles, timing ? What do you guys think ?

Train safely and have fun