Did you read the report?
The "oreo cookie", anomaly D-LL, modelled at a depth consistant with the crystalline basement. In layman's terms, it isn't shallow enough to be a kimberlite.
In the author's own words: "Unfortunately, because Anomaly D-LL appears to be caused by a feature in the magnetic basement, at this time this particular anomaly offers little potential of being related to kimberlite mineralization."