There are not enough information in the text to dig more i guess...
But i would try simply : snap is taken at midnight. snap is restored at 2.30. There are potentially 2h30 hours lost.
By the way i would have done things differently in order to have a consistent snap (except if they managed it by the application):
•00:00 hrs Host IO stopped
•00:15 hrs Timefinder/Snap established of DMX source volumes
•00:30 hrs Open Replicator Hot Pull session activated
well, theoretically, there should be only 1:15 hours of data loss.
SNAP was activated at 00:00
Host IO stopped 00:15
Host IO restarted 01:30
SNAP restored 02:30
So, host was not writing for 1 hr 15 mins so the actual DL should be of 1.15 hrs
To be fair, i said 2.30 hours because the Host IO stopped and Host IO restarted is never guaranted. If another host is writing, to the volume, if an error is made withint the array with the Open Replicator copy process, etc... so i agree with you in a perfect world, but this is not a perfect world...