The original is the one with the covered entry and the door is painted red or orange.
Here is what Google saw in November 2011:
Here it was in March of 2011, from a different angle:
The extra door is on the left. The main front door is dark red at the end of a breezeway to the left of the garage.
In the comments below the article are reports of recent drive-bys. There is now a vine-covered trellis mostly hiding the extra door and a six-foot high gate to your left as you approach the breezeway.
The address is:
3872 Duncan Pl
Palo Alto, CA 94306
Go see for yourself.
Four bedrooms, three baths, 2213 sq. ft. Built in 1953. Zestimated to be worth $3.3m. Zillow notes a 753 sq. ft. addition.
Also, the extra space is apparently occupied by Dr. Sylvia Adkins Randall, Phd, a specialist in group psychotherapy. Neither a student nor a Googler, it would seem.