Sir.

 The wear on the shaft. (ground A [from 1 plus 1])

 To show the gap/slop of the bearing. (ground A)

 The other one. As you can see, this one doesn't have any extra material, but is discolored in a different place. This one the heat affected zone was also a moving surface. Thus the need for a pin was evident.(ground B)

 The finger trap situation. (ground A)

 The finger trap situation- however on closer inspection this may have been something less- or different- from the original accusation.

1.There was no burnt mark on the handle (where they said the sparking happened)
2. No grounding wired fried, fused fried, or any other sign that anything actually happened.

 The length of the shoulder I whacked off 3/8" (modified for ground A)

 You can see the color change in the copper against a section that I cleaned/polished with a scotchbrite pad. (ground A)

 After I cleaned the surface I ran the ground together to see where it was contacting. This shows that contact as a shiner portion. (ground A)

 On the other ground (the one that spun where it shouldn't have) you can see the contact surface is on the outside only- as well as the purple hue from heat.(ground B)

 Same disc but with a polished zone. (ground B)

Also this one had been dropped. (ground A)