GtE
If I remember something I read once correctly, in a system whereby the fuel is pumped at high pressure, ie an electric pump as opposed to an engine driven pump, there is a danger, albeit it remote, that this pressure could result in the float chamber valve not being able to seat correctly, producing flooding and the associated risk of fire.
Don't know if this is anything to do with it, just an educated guess based on information from back of mind. At least if this question were to be asked of me, I think this is the answer I would come up with, rather than a 'blank stare'.
TJ