Gretel was shopping at a large shopping center and while walking through the crowded mall area, she saw a youth pushing his way through the crowd what appeared to be an attempt to escape from a man in a dark blue uniform who was following him. At the time, Gretel was standing near the exit of the building when the youth finally broke through the crowd and attempted to leave the building, she stepped in front of him to block his path. the youth collided with Gretel and two parties fell to floor. Gretel seize the fallen youth by the arm as he attempted to stand up and tried to push him back down to the floor, The youth then struck Gretel a blow on the side of his head with his hist, causing her to lose consciousness.

The youth as it turned out, was hurrying through the crowd in an attempt to catch a bus and a older man who was following him through the crowd as his father. The youth's father as employed as a security guard at the shopping center and was leaving work for the day.

Explain the incident in terms of tort law and tort liability?