He's joking because he has a hard timing finding any flaws. Trainers like Roach or Richardson never joke when they watch fight tapes.
On a serious answer , in the ring: Skill-wise: It's his punch accuracy, it's damn hard to out point him in a round Bonus: he measures the stance, opponent's movements - then he thinks and adjusts in-between rounds, and even as round progresses.
That elbow can get Floyd in big trouble in this fight Ortiz has a nice right southpaw uppercut and he uses it very well
I think its the straight right hand. He usually throws and lands it when the other guy isn't expecting it.