Yes, he said an insider sent him a coded handwritten message on a basis similar to a one-time pad.

He also said that he could not read most of said message due to misplacing the key-code.

EDIT: My original reply likely butchered terminology, sorry. The relevant audio can be heard verbatim at 1:03:11 in the interview recording.

If the OTP was used to encrypt the message, it's usefulness is already gone.

A source inside the NSA that re-uses a onetime pad would be pretty ironic.

Maybe Tice reads newspapers. Use of the datacenter would be nearly impossible to conceal. One can look at the power feeds with an IR camera and arrive at a reasonable estimate of power consumption. Also, water vapor from cooling equipment.

This isn't hard to believe. The scheduled "go live" time for the Utah facility was September 2013.