From my time on the forums here, I've seen many people do ask if "this was a lucid dream?" because they weren't aware, but they were still behaving as if they were. Some of these people do end up counting them towards their total. Personally, I'm positive my lucid count consists entirely of real LDs, maybe with a couple missed "false lucids" - if I do have a false one, I'll usually post it and say, "ugh, another dream in which I was pretending to be lucid..." but not count it.

But I agree, there's a fine line to draw between the "false" ones and real ones; you can act like you're lucid but not have the mental consciousness or capacity. Being lucid means to be aware and conscious, so if this isn't attained, it's not a lucid. IMO, it's a bit odd how such a seemingly simple definition can be misinterpreted.