"That oil rig worker"
As many posters (including me) have stated, an aircraft on MH370's track to SGN at FL350 would have been well below the horizon at the drilling rig's location.
An industry contact, who is in the offshore drilling business, told me that the purported author of the email exists and was working on the rig on the 8th.
Neither the owners of the rig nor the oil company that the rig is working for, was happy with this individual's actions. Not so much due to the unwanted publicity, but due to the deluge of communications from journalists.
Of course, the correct action for an individual in these circumstances would have been to contact the captain ( a drilling rig is a vessel, even though it is mostly anchored) and let him contact the appropriate SAR authority.
My contact speculated that this individual is probably no longer on the rig or even in Vietnam and is unlikely to be employed in the oil industry again.