He could not because the fight took place at Salt Lake City at 1.300 fucking meters over the seaBecause Costa has been a shadow of this Costa since after Romero fight. I am convinced he got busted for PEDs, hence long layoff and a delay in a fight vs Izzy, and why he is tested more frequently than anybody else except Jones. He couldn't even remotely reproduce this against a breathless corpse of Rockhold.
Imagine living all your life at sea level and suddenly you fight in the fucking peak of a fucking mountain
That would affect your performance or not?