The company has millions to gain from the contract and hasn’t shown morals on this issue.
The leaker has so much to lose by releasing the documents, everything from their career to a significant portion of their life. You could call that incentive to deceive, but I call it incentive to be just about their leak.
Especially when it’d be so easy for the company to leak counter examples showing moral consideration if they did...
Because Sundar Pichai has a strong public track record. Every CEO ends up with warts, but I have some sense of what he's about. The leaker, I have zero information on. Given known vs unknown, I put more faith in the known. Whether I by default believe or disbelieve depends on who's saying what.
Sundar Pichai's claim to fame was getting the Google Toolbar installer (and later the Chrome one) injected into the Adobe Reader installer. 
Don’t worry everyone it’s different now!
The point is that in any discussion, both sides have biases, and you need to take both sides into consideration to get a fuller picture.