This book excerpt really doesn't sound right. It would be nice to see a more detailed timeline - hopefully the book has one. But yeah, paying off a $450M loan so soon after a possible bankruptcy doesn't smell right. I can believe that Elon had an all hands sales focus after the NY Times Broder article - at the time Elon mentioned it did have an effect on orders. I will also say that I was more than a little surprised how quickly I got my car during that time period.
I ordered my car Thanksgiving weekend 2012 (late November 2012), and received it early March 2013. So less than 3 1/2 months, including a downtime period of Christmas. So there may very well have been a soft spot for orders around then. HOWEVER, I do not ever remember the factory being shutdown (except maybe for a week long Christmas break?), and certainly their sales numbers indicate that factory production was increasing all through late 2012 and through 2013.
So ... I'm very skeptical. Elon may very well have been talking to Google just as a backup plan. He IS very prudent that way - he had a secret backup plan for SpaceX after they blew up their first few rockets, and indeed he did use his SpaceX backup plan, so it wouldn't surprise me that Elon worked on a secret backup plan for Tesla.
But I think the article emphasis is wrong and over sensationalized. I don't think Tesla ever needed to seriously considering selling to Google. It was just there in case they didn't execute.
A final counter-counter point. In late 2012, Tesla stock was in the doldrums at $33 a share. The stock market response to the Model S sales and reception caught EVERYONE by surprise. NO ONE was predicting such a stratospheric rise to $100/share in such a short period of time. If Tesla needed to be saved, that's what did it - the public stock market. It allowed Elon to float a $1B debt offering (which occurred like 2 weeks after the stock price hit $100 if I remember correctly, an incredibly fast response).