As an airport, we could and would defuel on request into an empty bowser, subject to there being one, or indeed in a real emergency into a bowser with enough empty capacity.
All the fuel in the bowser was then returned to the storage tank, so that it would go through the same filtering and quality control system that fuel delivered by road bridger would go through. That would include checking for water, sediment and compatibility before putting it into storage, and quarantining the fuel until that was carried out with a satisfactory result.
However, the airport owned ran the fuel storage and supply facilities, buying the fuel from the oil company as it went into the storage, and was able to make irs own rules, within the
regulatory requirements.
The charges for doing this were rightly horrendous, but if it was needed at all, the process was worth paying for.
As a fuel supplier, who also did the handling and load control, we would question any strange uplift instructions from crews and prevented more than a few defuels becoming necessary.