Because Italy has a history of siding with terrorists and letting them go

https://en.wikipedia.org/wiki/Achille_Lauro_hijacking#Jurisd...

"Following a deal made with Yasser Arafat with Giulio Andreotti[25] even before the Craxi government had made its final decision, Abbas and Badrakkan, wearing unidentified uniforms, had been put back on the EgyptAir 737 airliner."