The case of copyright infringement for reproducing the same retouch effects on a slightly different photo (see the whole story here) seems a bit "open to abuse": in that particular case it may be correct, as the intent was likely to reproduce the original photo as closely as possible, but such a sentence may be dangerous if blindly applied.
Many Lightroom presets (and Photoshop actions) are freely available: does this imply that everyone who applied the same preset to a photo can be taken to court?
Furthermore, many presets are really similar (I have - say - 30 B&W presets, but I could probably delete half of them because either the differences are minimal, or they get the same final effect in different ways, but they are generally undistinguishable). But as a rule, one preset corresponds to a "mood", and two photos may want to convey the same mood.
In Lightroom there are only a few different ways to convert a photo to B&W. If I publish say 5 different presets called "Convert to B&W", I could sue everyone...