Needed to goto London hence decided to do a quick 4 day RTW flew from HK-LHR-JFK-HKG (for miles + 15k bonus offer). Was grilled at JFK immigration as to why I had just come from LHR and immediately flying back out to HK (and also resulted in a whole series of other questions). Had to end up explaining to the officer that a RTW was actually cheaper than a full fare business class ticket to LHR from HKG etc

Anyone had similar issues with US immigration recently?