If this was the case, why does he consistently reproduce it? Where are the failures? Does he only have one? Why has no one mentioned this failure rate? Or that it only works with material from a certain source? No one in science thinks these are unreasonable questions - they're usually very interesting!
There was a lot of work done finding the right source of talc for a particular medical procedure, because if they sourced it from somewhere else then it would turn out to be toxic. No one really knows why, although detailed study means we think it's now somewhat related to the -OH group concentration on the surface. Maybe.
The problem is, this isn't what's being relayed. Instead Rossi keeps details vague, because if you actually had details, you'd be able to go looking at the problem and actually do some science.