I think, recording is controlled by the EPG; ireespective of the programme's actual duration, recording is done as per the EPG setting , plus pre/post time settings. I am not sure what will happen if the broadcast programme is different from the title shown in the EPG.
Yes PVR is controlled by EPG. EPG puts a marker for Start & Stop time on particular channel (irrespective of actual programme running) and (any) programme within that time gets recorded
After power failure and power on, epg shows details not available for quite some time, before epg is updated.
As I mentioned above STB has received instruction to record particular channel at given time, so once PVR service is active after reboot, it will start recording
I will try different combinations of simulated power failure - in the middle of a programme, almost at the end of the time slot.
Please try and let us all know.