Talking about bonding , the escalation of bonding proved that not too many sparks, consultants, engineers etc fully understood the ( what was then) new concept. At one stage everything metal was bonded because people were scared of leaving something out . I remember old metal window frames in an office block being bonded , a G/yell X 4mm clipped through all the offices and drilled /tapped hole in every window frame .
I posted this one before , imagine one of those rubber door stops screwed to the floor in office toilets , the ones with a half cup of aluminium giving the rubber some strength ......yep...it was bonded!!!!
Another one on a hospital ward refurb, a low level partition with two hand washing basins back to back , the engineer picked us up 'cos our apprentice had only cross bonded the hot & cold pipes on one side . But its the same pipes ,we said, 10" long through the wall . Don't care , must be both sides . !!!
I tell you , Sparks would strap anything to earth if it didn't salute you back !
I see that all of a sudden , kitchen sink tops are not so deathly important anymore. You could be shot for not earthing a sink top often when it wasn't even there when you were there. But a plumber had no responsibility to do it if he fitted one but any passing Sparks was required to pounce upon it as soon as he saw it .