During the introductory levequest at the very beginning of the game, "Spore Spoor", the following appeared in my log:

Defeating targets will sometimes earn you experience points.
I believe this is a residual from before the battle adjustments, where it was once the case that defeating an enemy would give random amounts of experience, sometimes none. Things have of course changed. The word sometimes clearly requires removal.

And now I'm getting all nostalgic...