The bucket truck itself may not have really meant anything to someone who didn't understand what the outriggers, planted, mean.
A few cones with stakes and some danger tape may have cured that.
I've had the privilege of working in very pro-safety environments (and places with little training or concern for safety; worse than complacent, these guys had a contempt for safety concerns and procedures because it takes too long.)
I do believe (Partly because of liability) that we are the professionals and have a responsibility to protect the stupid from themselves (unfortunately) within reason; Darwin can have the unreasonably stupid ones.