1. You should be more aware of your surroundings. Don't turn your back for a second especially towards the person showing the most aggression which sounded like it was the man.
2. I don't really know of any. What i would have done, is just let the guy go where he wanted to. Don't resist against him by constantly blocking, but rather add momentum to him by stepping off the line of attack and then maybe giving him a push forward. If his momentum is great enough he will fall down.
As for being more aware of my surroundings, Amen. You are preaching to the choir at this point.
I understand the concept of moving off the line of attack, but I was in a bad position. My back was two feet from the counter and the aisle was only 2-3 feet wide. I didn't have any room to sidestep or spin. So I went forward the only direction I could see where I was going.
I also never turned my back on him. I just made the mistake of letting him get so close I couldn't see his hands.