This was likely a static electrical discharge that your wife experienced. The other arc is caused by the transfer of power (such as filling a capacitor) on the item being connected to the battery. So you have two entirely separate events.I understand what will is talking about.
The “arc” “spark” to the ring didn’t leave a mark. The touching of the bolt head with a cable not hooked to anything did.
Maybe the bms is shorted?
More of a concern is your interaction with SS. They seem to shoot themselves in the foot when it comes to CS. There is nothing worse than having one person promise something to have another say (or even the same person at a later date) something else.