mmm.... removal of positive or negative first..... Taught myself I guess when I was about 14`sh and allowed to "have a go" on my uncles motor. Despite that incident I did exactly the same as a young man with spectacular results. Certainly bettered 5th November.... Back when the batteries had lead links at the top of batteries from each cell... Managed to bridge the gap between one of these and some part of the engine or maybe bodywork. A huge bang... huge sparks every where and quite nasty burns to my right hand. The spanner actually flew away.. or maybe I tossed it with shock.... Thereafter always removed the earth first.. this mean`t that even if I touched the body or engine with the positive lead there was no problem.....  I wonder if the fact that electrons flow from negative, (cathode), to positive, (anode), comes into play regarding isolating negative.

This is a long going debate... Who` is wrong and who is right?.. Maybe nobody 100%..  What I can tell you is that what  DaveDnd says in his posts has some credibility and it`s also why I will never just trust a fuse alone. A battery has a "potential difference" between battery. 12 volts in your buggy. This PD remains at all switched items. On equipment that has components mounted on circuit boards I have found that in personal equipment and work related equipment the boards are "taken out", just as Dave`s photo shows, with absolute ease. It is a very common problem. We suffer frequently at my workplace with "power dips" & "voltage spikes". A fortune is spent replacing "control boards". I have very recently seen a boiler system with a low voltage control board that has been subject to a spike that left the positive supply fuse undamaged, a quick blow one at that, and the board was found to be heavily burnt and had been "on fire".   Electrics..... I believe in the "stray electron"     I have mention on the forum before that I have had a fire in a buggy. A "kill switch" in whichever battery lead that was easily reached would have saved a lot of time getting the battery disconnected. I was lucky..

strange thing electricity same as derusting  the rust flows from the neg and settles on the positive electrode so flows backwards.

For peace of mind and now habit , every time i get out of the buggy , whether for an hour or five minutes i turn off my battery cut off switch and my fuel shut off tap. When i refuel also and i also make sure i touch my stainless tank and roll bar to earth out any static electricity as with a rear mounted tank where the rear seats would be i am very aware of all the fuel vapor exiting the tank as i am refilling 👍💥😫

This has reminded my of a demonstration I attended in the early 70`s.... I doubt this could be done now due the health and safety stuff.

A gallon can of petrol was placed in a standard brick built council style garage. Can had the screw on cap removed and was left for about 30 minutes and the garage door was open..

Then the demonstrator used a remotely switched "ignitor" at the garage door. This was a sparking device. There was a loud whoomph and the can burst almost instantly. Huge flash of flame.

The purpose of this demonstration was to discourage people from storing petrol in cans in out buildings. Having used a garage as an example there was no mention that there would be a car in with petrol in it`s tank with a breather pipe.  No fire brigade present just a single ancient fire extinguisher