I have done lots of underslung work, including precision vertical reference live power line maintenance. And even in controlled conditions, it was hard sometimes just placing the blokes onto the lines from 60 feet up.
Dropping a load from 1000 feet up and it accidentally hitting a cable car or cable must have been extremely well timed.
Granted, airmanship and bloody unlucky, for both the people that died and the pilot...
Condolences to the families.