Questão jurídica principal
Whether the incident qualified as an accident under Art. 4 ATSG, especially the requirement of unusual external impact.
Decisão extraída
The event did not constitute an accident because the unusualness of the external factor was not proven with the required probability.
Fundamentação extraída
The court held that unusualness concerns the external factor itself, not its effects. The technical measurements of the device showed no unusually high sound emissions; medical causation alone cannot replace proof of an unusual external impact.