"....if I had been over Bahrain with smoke I would have pulled the throttles and speedbrakes and landed at Bahrain. Why go back to Dubai?"
They weren't "over Bahrain" - they were over the Persian Gulf somewhere. Reports say "100nm from Doha" - which could mean roughly halfway between Doha and Dubai (separated by a ~200-nm-wide bay), or somewhere else on the 100nm circle centered on Doha (and also 20 minutes at climb airspeed from Dubai).
(I haven't seen a map of their actual flight path anywhere yet - except for that ugly final minute.)
Bahrain was the ATC to whom they were talking at the time. But that doesn't mean they were over Bahrain any more than a pilot talking to Denver Center from NE Arizona or central Nebraska is "over" Denver.