In the aftermath, how would they know the cylinder was over-pressurized?If you get someone to cave fill your steel 95, and you have a completely unrelated accident while driving across the bridge to Solomons, and the damaged valve of the scuba cylinder in the back of your pickup shot off and killed the baby in the car behind you, I almost guarantee that your lawyer or opposing council would be sure to name the fill station, FSO, and person who put it in your truck to share in the bounty of the award, especially if there were a cool million in insurance to gather from the fill station.
It would be found empty and in a damaged state...
That becomes hearsay, unless there is some form of documentation managed...