In this case he was speaking on the phone , and that wasn't the subject matter in question. I k ow this because he was also speaking as if he were in his private office.

Certainly it's possible that some of the situations I've seen are of that type of origin - but IMO if you're interacting with a live human it's not an excuse. "I'm sorry , I just got terrible news" takes about two seconds to say.

I don't know, I see very little that could excuse the behavior. If someone is able to get into the store and conduct a transaction, then that person is generally able to acknowledge the person assisting him or her on a minimal level as a human.