James Randi, dishonest? He designed experiments that could not be tampered with in the way that skilled illusionists use. As a 'magician' himself he is intimately aware of the tricks that are available, so making a test to negate them all is absolutely demanded.
However, putting Randi to one side, anyone making extraordinary claims, and who wishes to be taken seriously, must submit to scientific scrutiny.
not to mention, it has been said by many a master that one should not go around showing off his level of achievement - and partially because of stuff like this, you will endlessly be subjected to verifications and will endlessly be hounded by people who want this or that level of proof of your 'powers.' and if you do not submit, then you are a faker, a fraud - nevermind what all of your students and patients have experienced.
And this is exactly what gets trotted out every time anyone says "okay, bring it, let's test it properly". If he, or anyone similar, had actual ability to do these things then they would be able to do them under very simple test conditions - bare room, paper provided by scientist, subject wears clothes provided by scientist, subject is thoroughly scrubbed before test, subject receives no visitors before test. There is no need for any 'device' to do measurements. The paper catching fire is an observable event measured by our own eyes. Nothing supernatural about that!
What John Chang does can be done by any reasonably skilled illusionist, or indeed any reasonably mischievous chemist. Ever seen the old fire in the hand trick? It is trivial. However, people like Chang seek approval only from people who want to believe it is true, and not seekers after the real truth.
I said it in earlier
"I know I can do it, why should have to prove it"
, and I stand by this. It is the most common excuse used by such people.
By turns this is both frustrating and laughable. Some people just badly want to believe in anything. Also, we are not talking about religion here. In matters of religious faith, proof is not required by the faithful (kind of the meaning of 'faith' really). In all other matters it is perfectly acceptable to examine closely claims such as those of Chang et al. If they choose not to comply in these examinations then that is an overt admission that they are relying on people to take them on 'faith'.
Excuses based "I don't need to prove...", or "it's not the done thing...", or "the master's disapprove.. " are all part of the smoke and mirrors game.