Stop blaming the ADs, plural, and you've finally got a defensible position, at least theoretically. To what end, I don't know.
Pat Summitt was the one who ended the series, as several folks have accurately informed you. As for your "more than one person is responsible:"
Yeah. You can add Summitt's staff, who went along with her. Surprise, surprise. Can just imagine them saying, "Forget it, Pat. Don't be such a jealous janet."
You can argue that the Tennessee AD should have stopped her.
Should have, that is, as viewed by you from on high. It was out of the question in the real world, where the power dynamics and relationship were such that there was no freakin' way.
Tennessee had a separate women's AD, Joan Cronan, until the AD's were merged last June. Summitt was the tail wagging the Tennessee women's athletics department, and Cronan was women's AD for 29 of Summitt's 38 years as coach.
Cronan: "We've always laughed because I wanted her to coach as long as she could, because she was a pretty good AD when she was coaching." (WBIR.com, 5/2/12)
So much for the Tennessee AD should've cracked the whip on Pat. She not only didn't crack it, she wrote the accusatory "we'd prefer to remain anonymous" poison pen letter about UConn to the SEC.
Turning to UConn, you can't plausibly argue the UConn AD, whether or not possessed of nerve, or anyone else on the UConn side, had the ability to keep the series going when Summitt decided it would end.
So, you're left with the abstract proposition that an AD should be the boss of a coach (and should, incidentally, have seen it your way). Fair enough, provided you recognize that, in reality, it isn't always the case (see, e.g., Paterno, J. and Summitt, P.)
And that's why people have a problem with your both-sides-were-to-blame sally. Whatever your reason for advancing it, it suffers from the appreciable defect of being unsupportable.