Everything happens for a reason. If you were in Koos' shoes and paying yourself $300-$400K/yr on paper, why would you suddenly cut your own salary in light of new positive developments regarding NR2F6, new patents...
Afterall, Koos didn't take the cut when HemaX wasn't approved or during the silence of no news for months. It coincides with positive news, so no reason for Koos to see the need himself. The reduction in salary, most logically, is due to a reason beyond Koos.