No, this has happened enough times with motorcycles that I now of. I haven't heard of it with cars but given it's the same technology (if we can call it that), then it probably has happened. I wouldn't use them in a million years. I bought a pair and screwed one onto the end of my brake bleeding tube to use it as a one-person bleeder. This works the same way as having them on your calipers only much, much safer.Sounds like you didn't have them seated fully. Speed bleeders are just like normal bleeders except there is a valve inside. You still have to loosen them so that the fluid can flow through.
I read the comment about 'use these end of conversation' and didn't offer my observation that it's best not to because I knew I was going to get flamed. I thought it's better if you all took that dud advice and smashed your cars up. Because if you smash up your cars (and maybe kill yourselves) because someone recommended this crap product, I don't really care. I know about them and I don't use them and that's what matters to me.