I seriously doubt that the young fella got close enough to the line to actually touch it. This sounds like he was hit when he came within the minimum clearance distance of the line and an arc formed between the line, his body and the earthed tower he would have been holding on to.
Not a nice way to go IMO. You can only do so much with barriers and the like, determined people will circumvent these.
All of the 66kV stuff I've ever done has either been with the lines de-energised and earthed or wearing a heap of hot gear and using hot-sticks, from a distance. Electricity of this calibre has no friends, don't get in it's way.
When I was at school, the major point of warning was the overhead and easily climable railway electrification. We were told that poking sticks near them from the bridges would cause immediate death!
Rotherham has a National Grid 400kV switching station and the place is riddled with overhead lines. They must know of the danger surely or the schools are doing a pretty poor job of frightening them.
The dangers of these things was drummed into us from about 6 and continued each year until we were 16.
When we were 15, we had a speaker in who asked whether we thought a 13A socket had enough electricity to kill, some of us said no! Not sure how he worked it out but he said there was 5 times the amount required for a fatal shock.
I took my time, I hurried up, The choice was mine, I didn't think enough
In Ireland you occasionally see a message from ESB networks warning about the dangers of power lines on building sites or farms. They're pretty bland adverts these days and don't really strike the same level of fear of power lines into people that the old ads did.
Perhaps it's time they did a fresh batch with more modern production values. The current road safety ads are pretty disturbingly realistic.