I'm stuck for an expression that describes this example, which is similar to a "self-fulfilling prophecy" but is more complicated:

Someone claims, falsely, to be a dentist. Someone who likes that person, but doesn't realize he's not really a dentist, claims, falsely, that the guy did a fantastic job on his implants. He's sure his friend would do a fantastic job, he just needs a "helping hand" to get started.

So it's not "a prediction that causes itself to become true", it's "a little white lie that unwittingly advances a deception". "Self-serving" (one's own interests, often in disregard of the truth) is close but in this case there's no "self" in the action.

Not sure if my question is off-topic, but it's like this one.

  • The question you link to is four years old, and no longer considered an example of a good question on this site. This question is asking what to write, which is off-topic here. Closing, but perhaps you can edit this into a better question? More information about this site is available in our site tour. – Goodbye Stack Exchange Aug 26 '15 at 3:06
  • OK. I moved the question to English usage (english.stackexchange.com/questions/269236/…) – plugincontainer Aug 26 '15 at 4:12