Scroggins and Ramjet555's post at 4097
While I realize that you don't think that INMARSAT technicians can tell the time; one thing that they are reasonably good at is which satellite the signals are being received by. The position of handoff between Malaysia and Vietnam where you would have the explosion - is outside the footprint of the geostationary satellite that was receiving the pings for several HOURS. Mathematical lateration calculations put the last ping North West of Thailand received by a satellite whose footprint does not extend as far East as Thailand.