First Social Faux Pas

It was going to happen sooner or later - I was just hoping for later, not my second day in Germany. It happened with my landlord who I had met briefly the previous day. He came to fix the lock and automatically I said "Hello, how are you?". This may seem innocent enough but the strange expression he gave me indicated that I had clearly messed up as he said "Fine. Hello Miss Rxxxx. What terrible social faux pas had I committed? First, I should have included his last name, "Hello Mr. Wxxx". Second, I should not have asked him how he was as Germans consider this insincere unless you really mean it in which case they will REALLY tell you are. I recognized my social faux pas right away having been to Germany before and previously discussing this with J.P. but what could I do. Oh well, I could only hope that this will be the biggest social faux pas this expat in Germany will make, but somehow I don't think I'll get so lucky.