You are implying that everything he said or wrote may be instantaneously discredited if it transpires that he succumbed to illness...?
Andreas promoted/suggested not just one 'quick fix' but a dietary and lifestyle change: organ cleansing (liver, kidney, colon) and a change of PERSPECTIVE. What could possibly be so wrong with this approach? It has worked for thousands upon thousands of people and continues to do so everyday. Only a fool would think his methods fallacious when there is so much evidence to PROVE them effective.
If you question him then you question the purpose of this very site (in my opinion).