Plausible, but (1) wouldn’t some wreckage, including the black box, have show up by now? and (2) isn’t it kind of a coinky-dink that the plane was carrying Iranians with stolen passports that were used last year to get into Muslim northern China on a very suspicious venture?
I can readily believe that an heroic pilot would have tried to deal with a hijack attempt by hooking a left toward the nearest airport in an effort to get his ship on the ground.
Do a google search of the Indian Ocean. Take a look at how big it is.