I agree it could be all of the above. But I think a single 2 pound sUAV would more often have minor damage with no loss in power. They will ingest a single 5 pound bird with no loss in power and I cannot see a 2 pound sUAV causing more damage than a 5 pound bird. Now a bizjet, or older airline, or military plane depending on the plane may cause loss of power, but airliners are built to different standards.