Silbury Hill 180
Image by Meic

Pete, the text I quoted was from EH's published article by Rob Harding, Amanda Chadburn, Fachtna McAvoy and Gill Campbell, and the answer to my question was delivered publicly in the Forum by Dr Brown. No scaremongering.

Until they start tunneling no one knows for sure what is going on inside.
Its all guess work based on flawed scans from Skanska and some low quality video footage from the bore holes taken 2 years ago.
I can't wait for for the tunneling to start.