If you return to the Morningstar Holdings link (below)Start in the Equity Ownership Box. Click the "Institutions" tab instead of the "Funds" tab. Note that U.S. statistics on Canadian companies are frequently incorrect on institutional ownership.
But, the line for Oceana says they increased by 14,344,931 to get to 39,342,592 total shares, before selling about 2.5mm I think. So it is possible Oceana had a big net gain. It is also possible Morningstar's data lagged. I notice Goldcorp's entire holding is shown as an increase, which we know is not the case.
https://investors.morningstar.com/ownership/shareholders-overview.html?t=GSV