But the means by which the referendum was done means that the claim that Crimea is now part of Russia is illegitimate.
No, no, the Crimea is very clearly part of Russia now and there's no particular point in denying that (unless you're a diplomat or something). But it was incorporated into the Russian state in a manner that is no longer regarded as entirely proper (even if it was historically just the way things were done), a fact not changed (not one bit) by the hilariously crass rubber stamping via questionable plebiscite.
That's mostly what I meant, yeah. I meant that despite it being part of Russia
now and by all indications going to stay that way, it's not legitimately Russian. The tactics are illegal and unethical, even if the end result was plausible.