Why is Satan able to snatch a snatch despite the strict guarding, and can he be prevented from hearing without being snatched or having a meteor strike him?

Ibn Kathir, in his exegesis of a verse from Surah As-Saffat, indicates that the devils snatch the word they hear from the heavens and cast it down to those beneath them. The meteor may strike it before it is cast, or it may be cast before the meteor burns it. This is supported by a Prophetic Hadith that describes how the angels flap their wings in submission to Allah’s command, and how the eavesdropper hears the word and casts it down to those beneath him until it reaches the soothsayer or sorcerer. The meteor may strike him before he casts it, or he may cast it before it strikes him, whereupon he adds a hundred lies to it, and people believe it because of that one truthful word. What the eavesdropper snatches is by Allah’s decree. This matter is a trial to distinguish those who believe in the unseen from those who believe that knowledge of the unseen rests with soothsayers and sorcerers.