I'm a line maintainer in Canada , some things here make little sense to me. If there was a primary up top and a neutral below arranged vertically on the pole how did he manage to short both of them on the cylinder. Was the truck grounded ? (it should be, to protect workers on the ground). Has the truck been dielectrically tested ? ( it must be yearly to work around hydro lines ). Great ideas about hold offs on the circuit but that is not for personal protection, only equipment protection. ( hydro owned equipment not your truck ). And finally limits of approach are for trained and qualified through training and experience employees , they vary with voltage and if any coverup is applied to the conductor, furthermore you should be wearing voltage appropriate rubber gloves around live conductors.