Coff,
It looks like the load on the SPAD system is an APFC (Air Portable Fuel Container ) or a variant thereof. The inherent flexibility in the rubber absorbed the various forces involved in the drop. If it could withstand being dropped by ULLA then it would survive almost anything. The APFC was designed to provide instant fuel stocks in remote locations for a/c, vehicles and in particular helis.
No doubt someone can elaborate.