Below is a quote from the solicitors who brought the case. I'm not sure on what basis the requirement is for solely NE to be satisfied is, but that would seem to be the crux of it.
https://www.leighday.co.uk/News/2019...allenges-NaturThis condition states that before issuing these licences Natural England – and not any other body or person – has to be satisfied that there are no alternative solutions to killing wild birds. Natural England has not done that. It has instead told licence users that they must themselves decide whether alternative solutions are ineffective or impracticable.