A pump of unknown quality and certification, installed by someone other than a licensed electrician, then said pump is connected to the camper batteries (not the FWC outlet since that would be 110V shore power, not 12V). And by the way, while that 12V auto/marine battery is much less likely to kill you, using 110V to power a faulty bilge pump can certainly kill you, if not give you an eye popping shock.
Water is inherently a poor conductor of electricity. However, many springs and sources of water at campgrounds come from wells which generally contain high levels of minerals. This minerals float freely in water thus enabling water to conduct electricity. If the a submerged bilge pump used to transfer water into the camper's tank is faulty or poorly/improperly wired, the electrical charge from the battery can easily be transferred to the camper, thus shocking anyone (grounded) touching the camper.
Given that we are often camping far from medical help and/or facilities, I see a submersed bilge pump used to transfer water into the camper's tank as introducing an element of risk that can easily be avoided altogether. I am by no means adverse to taking calculated risks, but, I will always default to good risk management and avoid needlessly taking risks that can involve possible injury when there are alternatives which eliminate the risk of injury.
And as I mentioned earlier, each to his own...each one of us has to determine our exposure to risk.
It only takes 100mA (0.1 w/v) to stop your heart!
I think I will pass on a submerged bilge pump and continue to use my 12V "dry" pump with a suction hose stuck in my water can and the output hose stuck into my camper's water tank receptacle.