<sarcasm> Perhaps we misinterpret "crush the test" as well....</sarcasm>
By this time, IH knew, I suspect, that Rossi was setting up to claim that the Doral installation was a "Guarantee Performance Test," which, unless they made some major blunder that has not yet been alleged by Rossi, it wasn't.
I would still interpret "crush the tests" as "get maximum information from them."
If they wanted to stop that operation, they could have at any time. It would have involved confronting Rossi, though, and may have have become public if legal action were required.
They could have stopped paying Penon and Fabiani (and might have pulled Barry West out). Those were not an obligation.... but they still wanted maximum information about the Plant and what Rossi would do.
What they did was to demonstrate how totally unreliable and dangerous Rossi is as a business partner. This is probably irreversible damage. If he does invent something useful, he will need someone to front it for him.
He's never trusted anyone to that extent. Paranoia strikes deep.