Well. My tactical analysis is that he didn't have good situational awareness, because he didn't see the 4 additional attackers coming. He was also baited by the woman and because he reacted angrily with a strike, the 4 other attackers got the cue to swarm. What he could have done is compartmentalize the shock and anger of being struck, while seeking an advantageous position. The best move would be to quickly turn and retreat to a chokepoint where only one attacker can approach at a time. Preferably something like a narrow stairwell where you can take the high ground and punish attackers with gravity. Using the environment for tactical advantage rather than being baited into an attack in the open while surrounded. Considering the dangers of multiple attackers, he should have resorted to a variety of improvised weapon attacks. He could swing his heavy backpack like a club to bludgeon and entangle one attacker, and then he could draw a concealed weapon like a metal pen from his pocket. Totally legal in any and all places, nobody suspects the pen, but if you get a high quality metal pen it makes an excellent stabbing tool and then you can deliver a series of sharp quick stabbing thrusts to the vitals of the attackers. A hit anywhere in the face with the sharp end of a pen is likely to destroy the morale of attackers and send them fleeing.