Yeah, unfortunately that's an issue that's hard to work around.
Without hard-coding information about each encounter, there isn't a way to tell from logs if the enemy was out of range, out of combat, or if you just were ignoring it.
So for these types of fights it'll just have to be accepted that the section won't show 100% uptime, but you can still compare values across fights to see when you did better than other attempts. Maybe once I have all the specs in a good place I can start adding exceptions for certain encounters, but that's a pretty low priority at the moment.
I've just added the most basic stuff for now, and will come back later to fill in talents and other abilities in more detail.