I thought I had argued in the talk that for some purposes logic was not the best form of representation or medium for reasoning with. But I probably was not clear enough in my presentation.

No, you did argue that, and I think we agree. But I would still argue that most, if not all, of your examples were reducible to logic, even if that were not the appropriate medium for either knowledge aquisition or proof discovery, though it might be an appropriate medium for proof checking...