Ok people lets get some facts. The aircraft was gone for about 5 and a half hours, block to block. So the 3 hours out of Manila theory and 3 hours out of AUH are shot. Second of all engine problems does not always mean they were operating single engine. A high engine vibration could cause a a/c to turn back without having to shut it down just throttle back some. Also depending on the track used that day it is very possible if they did have to shut down later that a suitable airport was only 1 to i 1/2 hours away max (see OPKC, OOMS, VAAH).
Last of all the company policy would have had them put in at the nearest suitable if they were single engine (commercial considerations, or maintenance are not considered in this case). Something to think about before criticizing our colleagues without facts.
AUH