How could the first, fourth and fifth posts in your screen cap be Public and not be visible to your friends, too? Looks like LJ has a bug to me. (In which case, LJ does not have a privacy leak as I stated in my last comment: in fact, LJ is doing the exact opposite and showing some of your public posts as not being available to your friends to read - and that's impossible, I'm sorry.)

(edit) Unless...OK, think I got it...tags worked the same way there as here until last week, so on LJ right now if you split a tag up amongst public and friends posts, the friends posts count won't show because the rounding up is done in the public post's column. Got it! It is indeed the same bug we had, and that's what the bug looks like once my Suggestion here is implemented there. This won't happen on DW now, though, because swaldman patched the bug last week, promise. :)