Personally I find your idealism in this topic not in tune with real world expectations. I am all for top-notch products through a means of rigid quality testing procedures, but who isn't? The fact of the matter is that you will never find products completely pure 100% of the time, and anyone in business will tell you that (unless they are part of the sales team)
Your expectations of absolute and complete purity and standards testing will not always be met IMO, regardless of what company it is. I take this as a part of the way a business functions, whatever their product or service may be. We can only seek to find companies that minimize this margin of error to a degree that satisfies us personally, as consumers.
This leaves us with the gray area, which is reality, not black and white idealism. You choose to not trust this company because of 3 products that contained trace amounts of DHEA, and that is fine. IMO that is not enough of a basis to speculate as to the quality of all of their products and/or the integrity of the company. If more tests were done on various products and/or the chemical makeup of the products tested were grossly inaccurate then I could say I don't trust them, but until that time I think of it as an example of the peanut warning as stated above.