Friend of mine is on EI823 from CDG which was due in around the same time, and diverted to SNN also. She's spitting feathers that while an earlier Aer Lingus flight also diverted to SNN, the Ryanair flight between them got in.. I'm trying to provide a rational explanation for this.. I assume FR just got lucky with a gap in the weather? Or is it a hardware issue? Or different company SOPs?