The website of the United States Powered Paragliding Association describes what could have happened if the carabiner had slipped just a little more:
This pilot was quite close to a catastrophic situation on two fronts. One, a significant bump that unloaded that riser could have caused the riser to come completely out, leaving the pilot spiraling uncontrollably down on the remaining side. Two, the carabiner has dramatically less strength and a strong updraft could break it.
Here's my question: was this picture taken during or after the flight? If during, then, sir, the people of the Internet thank you for thinking of us first.
Link (scroll down) -via reddit | Photo: Stefan Obenauer