Basically, the consultants who prepared the report and whose name is at stake, did not feel comfortable enough at that time, based on the number of data available, to include the silver data.

I'm no miner either, but the legacy silver data were collected many moons ago, when the analytical equipment may not be as sensitive, and silver might have been considered of little value and the sample size may be small. When there are inconsistencies between these legacy data and data generated more recently, the consultant might want more work done before he feels comfortable to include them. (To me this indicates the current data likely found much higher silver - the data are "inconsistent".) It appears to me that whatever the consultant needed to satisfy him has now been done and he is prepared to include them in the RE.