It's not that stuff is top secret, it's that information access is regulated to those who aren't full-time employees. Interns (green IDs) and contractors (red IDs) are given what they need to perform their job role, and little more than that. This guy was beginning to look at information he wasn't allowed to, and that should have been fairly clear to him. It's not that there is something to "hide", it's that information is limited for temporary employees, and that's just normal information security practice at any company of real size.
In regards to the race claim he's fishing for, I think it's rubbish. Regardless of what the make up of the temporary workers at 3.14 are, I see lots of contractors who are non-white (and contractors get access to most perks), lots of full-time employees are Indian and Asian. He's trying to draw out some conclusion that Google has discriminatory hiring practices based on the lower-income, lower-skilled jobs being made up of non-white, but that's just the statistical make-up of that demographic in California.