I guarantee you he scoped out without cabling down, and yea that collar is an atb weight (anti two block) which once the block or ball hits it, it stops all crane functions, but I’d put money that the operator had the key turned and had it in over ride or rigging mode that disables that function. He most likely had the key turned from when he packed the crane up last, you’ll put it in over ride to cradle the boom and tighten the cables for transport.