Nope, quite the opposite.

Treating all guns as loaded should be common sense since the gun in question (per the quote) is in your control and you are responsible for the potentially destructive results. This means you should be very familiar with this tool that you control.

The downed power line is every bit as potentially destructive but the power is not in your control and is probably under some automatic control that includes cycled resets. With downed power lines all you control is your actions.

Maybe it would help to think of the downed power line as an firearm that someone is pointing at you ? At that point I am going to assume it is loaded no matter what the ill considered person on the other end says.

- Eric