These guys are supposed to feel like this. Fighters are supposed to be confident, even when you loose.*
If i was his Trainer I would expect him to have this exact attitude towards his loss. Take it, learn from it, gain confidence knowing that your opponent won't get lucky again.
What good would it do if a fighter feels that '10 times out of 10 that other dude will always kick my ass'. None.
I know we saw the fight and Cain schooled his ass but thats the right attitude imho. If your gonna compete you gotta believe you can beat ANYBODY.Even if they just kicked your ass.