I'm not sure about you HV guys in the US, but spiking a cable is pretty much a standard procedure here.
Considering that you can do it from a distance, it is better (and safer) than putting a Sawzall into an 11kV cable and finding out otherwise.
The only saving grace about this accident was the fact that the person was wearing proper PPE and avoided some rather serious burns.
However, there is no excuse for an accident like this to have happened in the first place,
identifying cables is one of the simplest skills taught to Line-Mechanic/Cable Jointers here.