That's a
very generous reading of the situation.
At 14.36:40 hrs the Flight Crew replied “Ah we are level Flight Level Two Zero Zero and squawking Six Three Zero Four”. Shannon Low Level Control then said “November One Three One Zero Hotel Shannon radar contact and just confirm your passing altitude”. At 14.36:51 hrs the Flight Crew replied “We were cleared only to Flight Level Two Zero Zero”. Shannon Low Level Control persisted “Okay sir that’s copied but your passing altitude...your current altitude”. At 14.36:59 hrs the Flight Crew replied “And we confirm that we are cleared up to Flight Level Zero Two Zero… Two Thousand feet”.
There's really no question in my mind but that they felt that FL200 represented 2,000 feet and thus they were level at their clearance.
Edit: Never mind the fact that they did
not ask for clarification.