Whether Data was officially a person or not, the whole point was that for all intents and purposes, he was one. I think they were trying to recreate the dynamic between Spock and McCoy in the original series. The problem was, in TOS, it worked because Spock gave as good as he got. Data would just look confused at why…

I brought this up some time ago (for some stupid reason), because Nurse Chapel says "Dr. McCoy?" and both Bones and Beast annoyingly answer her. Comic gold, dammit!