I'm not using "software QA" in the very broad way you describe in the first sentence. Also, "defect" as I use it does not mean every short-coming of the product. It means "something doesn't work (or failed) as designed or required."

Context: my blog posts are meant to contrast with "experts" who claimed that poisoning social AI was just in the nature of learning systems, even when they worked as designed (i.e. had no defects). They are claiming that Tay learned to be foul mouthed and racist, and thus had become foul mouthed and racist.

If that were true, then this undesirable behavior would not be a software QA problem. The AI would be working as designed. No QA process would change things.

In contrast, I'm claiming (from evidence) that the main problem in Tay is due to a hidden feature in a reused library + rule set that should have been detected and removed in a QA process that considered various attacks. BTW, this attack (getting bot to repeat naughty words) has been around since ELIZA in the 60s.

The other failings of Tay (esp. no black list) are design and requirement failures, not QA failures.