On the face of it it does appear to be about the simplest thing to test you
could imagine. You really only have to measure two things, the amount of
electricity going in and the temperature increase in X litres of water in
the device. Multiply that by the specific heat of water and see if you have
more joules coming out than going in. A morning's work for any semi
competent physicist.

To re-quote my earlier post:

"According to Prof Smith, if there is a flaw in the company's claims,
it lies in the measurement of the amount of electrical energy pumped
into the cell. It is possible that, as sparks pass between the
electrodes, there is an energy surge which would not be picked up by
the instruments measuring the electrical input."