Sorry to disrupt the BFO things, but why the 00:11 handshake has been at this time and not at 00:15?
A phone call at 18:41 (channel released at 18:40:56.354) seems to have zeroed the one hour timer at 18:41, so the handshakes at 19:41, 20:41; 21:41 and 22:41. All of them in a ± 30 seconds interval. The next would have been at 23:41, but there was another phone call at 23:13:58.407 with the channel release at 23:15:01.886. This might have reset the one hour timer and without any contact, we would expect the next handshake at 00:15. And later, it was at 01:15:56 (so a two hours + 56 sec from the time of the phone channel release) that a not answered handshake from the sat happened, because the "partial handshake" of 00:19 would have not reset the timer.
But why a 4 minutes early HS at 0:11? From the Inmarsat data, it has been clearly initiated by the sat.
Just a remark. At 00:19, the whole larger search zone (the grey zone, page 42, 47 of the PDF) was in daylight, with the sun just rising near 40S 85E, and about 20° above horizon near 17S 107E (at sea level).