What if the US were to execute as well as Europe in the big moments in matches? In the end, pedigrees shine brightest when matches hang in the balance, and when the finish line has been in sight, Europe has tended to execute very well, while the US has missed opportunities, especially in the Robinson vs Kaci singles match and the SVB/Thorpe double match that got away when Shane hooked Billy with the finish line in sight. As you note, had he won the safety battle on the four against Shaw he wins that match, too.
In the end, the "what if" that really matters is "What if we played as well as they do?" If we did , we'd do better when opportunities knocked, but we don't. Team Europe's pocketing has been better, their position play has been better, and their speed control has been better. That has made them tough to beat.