Fuel will flow when you loosen the banjo bolt...This does not mean the filter is okay !.
The noise you heard is the pumps trying to get fuel.....they run for a second or so after the engine stops....they are activated by the ignition spark signal with a delay programmed into the relay/ecu, so the pump runs for a second when you turn 'on' the key and for a second or so when the motor stalls and it looses the ignition signal.
Pumps make a noise when they are starved for fuel or they are fixing to quit.
The line nut and banjo bolt are tight....you'll need a metric wrench to undo them as well as a back up wrench, to stop the fitting from spinning on you.
Change the fuel filter, already !!!!!
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