That's exactly what hand-waving is. It's bad logic they use to support a conclusion that they then immediately hedge in the following sentence.

Here's the 10 safety essentials check list they are talking about:

http://www.healthcareimprovementscotland.org/news_and_events...

If the checklist is responsible for all of the improvement in surgical outcomes then we can stop doing the rest of the stuff, right? No need to emphasize hand washing or sterile central line because the magic checklist will stop the infection.