Well, I forgave them the "blow torch," given translation errors and most peoples' lack of gas torch expertise. On the other hand, maybe they were trying to loosen the detonator with heat. I doubt there's enough evidence left to determine what they were actually trying, unless witnesses survived.
But jeeze, you'd think everybody would know what a 500 lb bomb casing looked like and be smart enough to call the cops or army for UXB disposal.