I guess any particular details of investigation will be classified but still it is a good question how exactly did it happened. Press is reporting both Spanish Eurofighters serving policy mission in Baltics are called back to Spain with immediate effect. Whatever happened it is a good luck it was north-bound and did not captured any civil airliner around the area. Be it east-bound, there is Russian 76s Airborne Troops Division based in Pskov, well within AMRAAM reach from the firing point - imagine the consequences!