"Facebook chatbot shut down" doesn't really show anything. It was a everyday failure of training that got overblown in the media.
"Google AI looks at rifles and sees helicopters": This wasn't new at all. Black box attacks have been around for a while. The paper purported to show a much more efficient attack, but it's not really a huge advancement.
In general, most of these aren't really what I would call "failures" of AI. Some of them are illuminating parts of ML that are problems (copying society's bias, adversarial attacks), but most of the rest are simply things being overhyped/regular design errors (anything to do with Alexa/google home).