One of the surviving passengers quoted in news bulletins (Reuters, CNN, BBC, etc) was noted as saying he observed "fuel pouring out like a water tap"...surely engine and guel gauges weren't being monitored during take off run to catch that. The fuel leak problem could have been evident at pre-flight but it might have been raining and less evident.
You're way ahead of the game and speculating. A fuel leak from the HP fuel pump won't be obvious with the engine not running AND it wouldn't show up as abnormal fuel flow.
That exact situation occurred in AA's first A300 revenue flight.
Let the investigation run it's course.