Matt negligently takes his eyes off the road while driving through an intersection. Angela is crossing the intersection at the time. When Matt sees Angela, he swerves his car to try and avoid hitting her. In swerving his car, he crashes into a brick wall. The brick wall begins to crumble. The crumbling wall knocks over a tree standing next to it. The tree falls, lands on Angela and breaks her arm. In a word, ONE WORD, what is the primary legal issue in this problem (hint: the word is not “negligence”)?