I think you're misunderstanding what he means. He's saying that Google employees don't have access to that kind of information (due to access controls, logging of access, etc), likely in response to your "would you be uncomfortable with your friends collecting arbitrary amounts of data from you" question.
I'm not saying that his comment was a sound rebuttal to yours or anything; just noting that he was talking in the context of "your friends, neighbors and former coworkers" accessing your data and you're talking about "Google" accessing your data, and those are potentially very different things.
Yes. User data, especially PII data, is very closely watched. If I tried to access something that I shouldn't (assuming that I managed to get the right permissions first), I have no doubt that I'd be fired by the end of the week.
Even twenty years ago, if you called a mail order catalog company, and it was the first time you'd called them, the sales rep on the phone already had your number (from commercial caller ID), your name (either "Bob Smith" or "Sally Smith"), and your household's credit card numbers before you even opened your mouth. They would still ask you for them for security reasons, to see which of your cards you wanted to use, to double-check accuracy, and in order to NOT freak you out, but companies you had never heard of already knew your name before you ever called them.
But you think Google can't figure out my name?