I had a similar experience with a Google phone interview once. The interviewer asked me about a technology I knew almost nothing about, and I told him right of

I had a similar experience with a Google phone interview once. The interviewer asked me about a technology I knew almost nothing about, and I told him right off the bat that I didn't know much about it but I would explain what little I did know. But then he spent the next 20 minutes asking me more questions about it, how I'd use it, how it could be implemented, etc.. It was so frustrating I should have just ended the call early.