Actually, he didn't:
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and
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- The technique was still in progress and Mifune was jostled out without a single contact, when given KA's 'lack of realization' clause, he should have continued to be in trance. This is backed by how Itrachi was completely broken out Edo Hold. Heck, even regular Sharingan genjutsu requires far more effort than this pathetic display. Remember Chee and Orochimaru?
Both are genjutsu specialists and were beaten so easily with 3 Tomoe genjutsu by Sasuke. Chee couldn't move even if Darui jostled him out of it and yet, Mifune snapped out of KA when someone pointed it out? Face it, Danzo's use of KA is borderline pathetic.
In fact, he was checked for it and commented that the technique's limit ran out afterwards. Mei's guard specifically used the term currently:
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.
Mei has compared to Genjutsu -
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. Even at regular 3 T level, Sharingan is fully capable of defeating any Genjutsu specialist. Before you suggest she didn't state 'Sharingan'. It's blatantly obvious that the analogy is being created with Sharingan as all villages are aware of how to tackle an Uchiha who has awakened his Bloodline limit. She is thinking that Danzo was behind it. You can also look at the above reply.
As for Shisui's KA feat? I don't think I need to post any scans for it. Kabuto was inevitably defeated because of the aid it provided.