And even Voisey's bay needed to do a strategic sale before they got the true value of the deposit in a buyout

They did not really NEED to, they were approached by the partner and asked if they could buy in some small percentage at a very good price (for DFR). Friedland saw it as a way to leverage a higher price for the full deposit. If I recall (and i just re-read the darn book ) part of the deal was IF a large buyer came in for the whole deposit the partner had to vote whatever way the BOD did. So, in a sense it PROTECTED against a hostile bid.