The problem I have with this question - other than I don't think it's a very good question to "immediately disqualify" someone on based on their answer - is tha

The problem I have with this question - other than I don't think it's a very good question to "immediately disqualify" someone on based on their answer - is that "the right answer" is formulaic. There is one answer that always works 100% of the time: Let's say you asked a senior candidate that question and they said, "Well, I'm an ambitious person with lofty career goals. I really want to get into project management. My biggest risk here is that I join, you don't recognize my contributions and promote me, and I end up leaving to join another group who does." That's all that has to be said. The "right" answer here is to reflect this back and show that the risk is mine (speaking as the candidate) - "I'm taking the risk here because you are the unknown."