I am going thru Mike Holt library 2011 videos and he runs a train over article 680 (and CMP). Especially over 680.26 (B) (7)
(7).All fixed metal parts shall be bonded
including, but not limited to, metal-sheathed cables and race- ways, metal piping, metal awnings, metal fences, and metal
door and window frames.
That means window frames and gutters and rooftops. And probably a car if you park close by.
I do not do any work about that Article. Do you have any take on that?
The first part of understanding this is to understand there is a difference between grounding and bonding, in particular the "equipotential bonding" that is covered in that section and and why it is done.
Though an electrically isolated metal item is likely not much of a threat, should that item be "grounded" (not bonded) it introduces hazards.
Bonding require by that section brings all items subject to being touched by pool users to the same potential. This equipotential system could be operating at thousands of volts above true ground, but because everything in the user's reach is at the same potential it is no different to the user then a bird sitting on a high voltage line - he is isolated from other potential points.
Remember the grounding electrode system and equipment grounding conductor network of any premises is connected at the service equipment to the current carrying grounded conductor of the service. Any voltage drop on that service grounded conductor is also present on the GEC/EGC and anything bonded to them. So even if there is only a 1 volt drop on the service grounded conductor, that one volt will be present between the system and anything earthed but not bonded to the system - maybe a pool ladder that for some reason did not get bonded - a user may feel the effects here, if the voltage drop increases even more that likelihood only increases.
Then consider most areas the POCO uses the grounded neutral conductor of their primary system for current carrying and the fact that it is bonded to the secondary grounded conductors - you have a point of introduction of the voltage drop on the primary neutral into the picture as well. Many electrocutions you hear of at boat docks are caused by this very problem - they bring that potential to the area via the EGC of a boat hoist or something in the area of the dock and the problem voltage is simply voltage drop of either service or POCO primary neutral conductors and the potential to "true earth".
Sorry for being a little long winded - but hope it helps.