Yes, a good point, it does. Breyer's opinion does say the court is arguing that the API is copy-righted, but used under fair use (as opposed to not copy-righted, in which case fair use doesn't make sense). But my point about what seems to be the main distinction making it copy-right-but-fair-use is the declaration vs. implementation concern, a distinction that logically exists (so I think the outcome is correct!), but does not seem to legally exist.