In the cave, Regulus doesn’t beg for it to stop. He begs not be left behind, alone.
Perhaps this is why, when Kreacher gives one last look over his shoulder and sees terrible, pale hands reaching for his master, he appears in a flash at Regulus’ side, clutches him by the elbow, and Apparates them both out of the cave, directly disobeying his master’s last order.
Fantasia