Seems according to Rossi that an arrangement was made so neither party could have a look at the other's workings and it does make sense
It makes a lot of sense that a bona fide customer that Rossi searched for and found wouldn't want the public to have access to their facilities, or to know who they are, or to see what they had set up. It doesn't make a lick of sense that the "customer" in this instance wouldn't want IH to see into their facility, or that IH would have signed an agreement that this information would be kept secret from them, essentially taking Rossi's word on faith that the customer was anything other than a Leonardo fiction.
One conclusion that can definitely be drawn from what information is now publicly available, by the admission of Rossi and by what is disclosed in the lawsuit, is that Rossi had no intention of carrying out a test of the 1MW plant in a way that could have been rigorously verified by IH. If IH signed on to all of the details that we have heard through Mats and Rossi, such as signing away access to the customer facility, it was not looking after its own best interests. Whether it was in fact will be clearer from its response to the suit and from the determination of the court. But it in any other context it would be redonkulous for IH not to be allowed to see the customer facility, as it is in this context.