To "uncock" a DST, simply put the action on "Safe", pull the rear trigger with your middle finger and touch the front trigger with the index finger, then ease the rear trigger forward. Takes some practice. A single set trigger can be unset the same way, by putting the rifle on "Safe" and simply touching the trigger off. In both cases, the muzzle should naturally be pointed in a safe direction.

A friend of mine was shooting his Krieghoff Teck .458 WM O/U double rifle in the usual sequence of front trigger first, rear trigger second, when he decided to reverse the sequence. Unfortunately, he forgot that he had already set the front trigger. He ended up with a nice half moon scar over his eyebrow and a bent scope tube when both barrels went off in rapid sequence. I would never have a set trigger on a rifle for dangerous game.