I mean, it's more or less confirmed that he either broke or severely injured Geo's arm with that kimura, so I don't really think that's accurate. Keep in mind also that there Ishii's background consists almost entirely of gi-based submissions, and there isn't really such a thing as no-gi judo, so it makes sense his finishing ability wouldn't be as good without it.
I can't find anything official, I just remember reading a lot right after the event about how that kimura really messed up Geo's arms. It wouldn't surprise me if it was true, since it looks like it got wrenched severely.