I think the assumption is that any wire that got pinched was internal to the ELT, so nothing to do with the airplane wiring. I'm puzzled by this insulation thing, it really didn't look much different from type 44 and the 230V wiring was better (thicker) insulated so no real difference from most airplane wires. I can always be proved wrong of course - it happens a lot! - but as far as this incident is concerned, the ships wiring could be a bit of a red herring.
rather than much tougher PVC based coverings....
PVC insulation is not permitted on aircraft, toxic when lit!