I've been through this as well for a very senior role:

Interviewer: "Do you know X?"

Me: "Yes"

Interviewer: "Great, do you know Y?"

Me: "Sure" (starting to get suspicious)

Interviewer: "Nice, how about Z?"

Me: "Aha" (not believing this)

Interviewer: "When can you start?"

....

This is the opposite side of the coin. This quick-fire hiring is scary and detrimental. What would that tell you about the company? :)