yorkshire tyke excellent question.
Who does deal with an overfuelled aircraft and who must legally deal with an overfuelled aircraft?
Many airlines request their engineers to deal with fuelling in general. Many don't. The reason many don't is because it is not maintenance and does not require qualified engineers to perform the job.
Tyre pressures however are technical and it is considered a maintenance task. The subtle difference is that an over pressurised tyre is not in accordance with the maintenance manual, does require an approved engineer and a release to service. All of which has legal implications.
Too much fuel is too much fuel yet the aircraft is still within the maintenance manual limits and does not legally require a release to service. This makes a huge legal difference.
An engineer may out of the goodness of his heart assist any apparently responsible person who allowed such a gross refuelling error take place but the problem remains non technical.
It is that simple and no, not even Nicholas can argue around it.