The slammed fist is one event that sticks out to me, but I've seen him often enough to say that he gets easily irritable if things don't go his way. He was happy as a clam last year, but he's a completely different man this year for obvious reasons. Seems like a dude that you don't want to get on his bad side.
I had this impression of him before, but after reading Nadal's book I'm positive his father is a calm and positive energy in his life. He has very high esteem and regard for his dad, and he speaks of him as the one member in his family that gets things done and finds solutions to Rafa's problems. When Rafa went through his bleakest period after discovering a genetic malformation of his left foot, and was told by the doctors that he would never play pro tennis again, it was his dad who looked up everywhere for a solution and his dad who cheered Rafa up and helped him recover psychologically. It gives me the impression Rafa values his dad's input in his career more than Toni's.