1) Datura, or Jimson Weed, is probably the most horrifying psychoactive plant and has no natural relationship to kava at all. Who knows where that article was coming from but you run a VERY low risk of getting kava contaminated with Jimson.
2) Adil is not blowing smoke. He has taken the time to have lengthy conversations with many of us on the phone or through other means to discuss his products and the proliferation of kava culture. He's the real deal, as are many of the other vendors on this forum and you can use this forum with confidence, imo, to make good decisions about kava. I have tried most of the kava's mentioned around here and they are, for the most part, all excellent.
These OTC extract/pill/tincture manufacturers are what you should really be cautious of. If anywhere, that's where you will likely run into problems (if not get ripped off).