I'm sorry, what? You're going to have to explain to me how Connally's WC testimony destroys the SBT. Because I don't see it. In fact, I see just the opposite.
Connally's WC testimony conflicts with a first-shot-SBT. Each of three independent bodies of witness evidence (1. that JFK reacted to the first shot, 2. that the first shot was after z190, and 3. that the last two shots were closer together) conflict with anything other than a first-shot-SBT. So, in that sense, Connally's WC testimony, if correct, would rule out the SBT.