is a principle that generally recommends, when faced with competing hypotheses that are equal in other respects, selecting the one that makes the fewest new assumptions.
In the case of the Oct 6th test, what are the competing hypotheses? I think that there can be only two: it works or it doesn't.
We have to assume that the conditions are what they are represented as being. In short, there is no secret energy source that can escape the notice of the observers. To postulate that there is one makes the assumption that this secret energy source can escape detection. Therefore, the energy produced must come from the E-cat apparatus itself.
Secondly, the measurement apparatus is reasonably accurate for the purposes of this test. This reason is self evident: if it was too inaccurate, this too would have been detected by the observers. To assume otherwise violates Occam's Razor because it introduces a new assumption once again.
Finally, it has to be the case that nothing is up the sleeves of some tricksters. This would require the assumption of some conspiracy amongst the observers to deceive everybody. Such a conspiracy would entail a large group of people present to be able to keep the tricks a secret. It seems unlikely to me. The larger the number of observers, the harder it is to keep a conspiracy secret. The more observers there are, the more likely that everything is as it appears to be. To say otherwise would violate the principle of Occam's Razor, as it would add a new assumption of a conspiracy.
Unless the naysayers can come up with an explanation that doesn't require these new assumptions, or does not require some form of another assumption not mentioned here, then the test is as represented.
From where I stand, the test looks like a success. The E-cat produces more energy than it consumes. That makes it a successful test. By the way, that is the simplest explanation too. In other words, it is as it appears to be.