He could not accept what chemists told him and other biologists told him. While technically meeting the criterion for life detection orginially propposed his experiment did it in a totally unexpected manner and in a context that did not fit with life
(ie the other experiments). He designed a good experiment, but interpreted it's results in a manner favorable to him personally rather than the facts. I like the idea of repeating his experiment with nonracemic mixtures, but he's so damaged his scientic reputation that it will probably never fly. For years he used the fig leaf that the chemists could not prove it was chemistry because they didn't identify the chemical involved while all the time ignoring that he couldn't find a life form to duplicate the results. When results in Altacama proved that the results could be duplicated in dry lifeless soil under conditions resembling Mars closer than any others on Earth he displayed his colors by upping the denial mode even higher. My low opinion of David was formed when he reported Levin's ranting response without rebuttle from the Altacama researchers and his personal reaction when I E-mailed him about that lack of fair journalism.

Regards,
Mark