FR delayed flights
Future 737NG pic(?)
I don't know the specific answer as to why FR flight were worse effected, I think the reason may partly be that they schedule much more tightly than most of the other airlines. ie shorter turnaround times. EI do short turnarounds on alot of flights but on a lot of european flights the turnaround can be as much as an hour and same for LHR. So I would suspect that Fr find it much harder to catch up once the schedule gets behind.