What determines the handshake ping timing and what could have delayed this final (complete) ping?
Inmarsat will know?
There are three "delayed" bursts:
1:07->2:25 = 1:12
2:28->3:40 = 1:12
6:40->8:11 = 1:31
The burst activity around 2:25 appears to count as one ping, otherwise the number of 6 pings received after 1:07 doesn't make sense. This activity may be attributed to the big change in relative speed between 1:07 and 2:25