This seems a bit strange. I know some senior Google folks who spend a ton of time interviewing. Could it be that these are maxed out, and that HR people are forced to do the initial screens? In that case it's best to just feed them the simplest accurate answers possible. Similar to taking the SATs.

This type of process does imply something about their recruiting funnel. HR people asking technical questions suggests they've historically passed too many technically deficient people to overworked senior engineers.