The clerk is just plain LUCKY to be alive. We have a tendency to rationalize 'all is well that ends well' and not learn from our mistakes and the mistakes of others. The clerk should have neutralized the threat without hesitation, HE DID NOT! It ended well THIS TIME but I have seem it not go this way for many who hesitated to pull the trigger when they had the chance.
This was simply 'testosterone' gone wild! In life and death situations you MUST NOT hesitate even for a split second or it may not end in your favor.
I am glad it ended the way it did, but that doesn't make it RIGHT!!!