based on what?
"Normal chaff goes out in minutes"
Do you really know what chaff is to make a comment like that? It is metallic confetti. No burning.
"booms" are usually caused by a jet going "supersonic". In the US they are prohibited from doing this over land. Can't speak to rules in Europe though.
No. This is. (pic related)
parachutists would not cause such a stark radar return. Deployment of chaff is the most logical answer.