He seemed unnerved... but not like a robot or a "computer-referee"... he was another person there, watching, feeling and understanding what was happening. He didn´t need to run desperatly but he was always near the actions. And, almost always, he decided well.
The game was not violent but a Libertadores game is never an easy job. Gaciba´s assistants didn´t help him too much (one of them seemed to have a spring in his arm). But the referee succeeded. It´s a bit early to consider this Brazilian as a great referee, but he is definitively one for the future.