Actually, his statement excuses his words but doesn’t actually apologize. Something liberals always do. It’s like saying, “If he was offended, then I apologize” as if there is any question that what he said was offensive. He did not come out and say “I apologize for what I said” and therefore tries to shift the responsibility back on the target of his words rather than taking responsibility himself.
I don’t see where he made his apology conditional the way you are suggesting. He called his own words “ad hominem” and “uncivil”, and said “for that, I am sorry”.
Now I’m not a fan of Takei’s politics, but he generally does have a reputation for high-minded discourse, and he seems to recognize that this was a time when he fell far short of that lofty goal, and the apology to me seems sincere and sufficient.