They're much more demanding than singles. In other words, he stalled the airplane. The FARs serve as the legal minimums, and since most skydiving aircraft operate under FAR Part 91, those requirements aren't very rigorous. These days insurance companies have a significant role in saying who may fly a jump aircraft and what sort of initial and refresher training he or she receives. Their requirements often go far beyond those established by the FAA, and they usually include periodic training.
Some aircraft operators require that their pilots practice emergency procedures.
But even when they do, the practice isn't very realistic. In other words, counting only accidents doesn't give an accurate picture of how competent our pilots really are. You're of course right in saying a pilot should have a plan before every takeoff, just like a skydiver should mentally review his emergency procedures before every jump. But you also realize a plan doesn't guarantee a successful outcome, especially when the situation is extra-critical. And it's always easy to criticize another aviator from the comfort of one's armchair.