My preferred mechanic (one of the few that I trust) is the owner of a LBS called Nelo's. He's an ex-racer Brazilian. He used to be the head mechanic for a few different professional bike teams and has wrenched on bikes at some of the most elite races in the world (Giro d'Italia). I've never seen him use a torque wrench. Do you know a more qualified mechanic than that?

Also, his shop now deals exclusively in Wilier, Kuota, Colnago, Cannondale and Tomassini...so it's not like he doesn't wrench on carbon bikes regularly.