Some of yall don't get it. Zoro didn't question King not being a Swordsman just because King "threw a punch." He made the comment because King doesn't care about traditional forms and techniques when it comes to wielding a Sword and fighting.
Zoro actually cares about traditional forms and techniques, but is willing to let that go if it means winning the fight.
The fact that King doesn't give a shit about form and technique when fighting, is what makes him not a Swordsman. He wields a Sword to help him in a fight, but doesn't wield a Sword for his primary means of fighting.