Last week's story evaluation

Before the Thanksgiving break last week we had the group assignment to define aggression and then read that short story and pick out what acts were aggression according to our definition. There tended to be several schools of thought on how it was defined and what specific actions in the story were indeed aggression. I was confused leaving class last week about one that several groups labeled as aggression that was later said to not be an act of aggression. I would like to take a moment to try and argue that it maybe was indeed an act of aggression.

The specific action I am talking about was, "Depressed and angry, the thief smashes his fist into the concrete cell wall, fracturing three fingers." This was labeled as not an act of aggression due to the fact that the thief did not hit the wall intending to destroy something and that the act of hitting the wall was not aimed at an "other" type thing. My argument is this: if aggression can be hot or a responsive action to strong emotion, then couldn't the thief have been acting on that emotion and the wall just happened to be the recipient of his outpouring anger?

The other example used that is closely related to the one above, "the thief angrily kicks and dents a waste container", this one labeled as aggression due to the fact that it was aimed at the destruction of an object, I feel really should be classified in the same category as the first one. The thief didn't kick the garbage can with the true intent of destroying it, he kicked the garbage can still acting on the same emotion that fueled the hitting of the wall. Therefore, if the garbage can example is aggression, couldn't we label the wall example aggression too? Also, if it isn't aggression, then what is it?