Well not that it will make a difference but the elder is wrong.
A person saying excuse me when they sneeze or step on someones foot - or a thank you is not breaking their restrictions as one disfellowshipped.
Its conversation that is "unscriptural" according to them. This would be anything conversational however brief, including saying a "greeting" such as "Hello" or "How Are You?" .
So they Pharisee elder just gulped a camel and strained at a gnat. He doesnt even know the finer technacalities of his own rules he is entrusted with enforcing.