If the satellite pings occurred every hour, and the last ping was at 8:11 a.m. KL time, and these Maldives witnesses did in fact see the plane at 8:15 a.m. KL time, then if the Goodfellow theory is correct the plane crashed not long after the sighting at Maldives, because there was no ping at 9:11 a.m.
The place to search for debris would be extrapolating the flight path from the Strait of Malacca to Kuda Huvadhoo and onward for up to 56 minutes of flying time.