The troublesome part here, is the stage in the program where this show up. Before the first failed launch, NASA willingly scrapped the first full wet rehearsal. It's all that says about the management of the testing phases and what implies for other parts of the program.
>Once again a leak in the same propellant line that forced the scrub during the Sept. 3 attempt gave NASA headaches. But teams were able to reset the flow of the fuel line, which minimized the leak to acceptable levels so that more than 730,000 gallons of cryogenic propellant were loaded into the rocket.
Just one of several significant problems associated with efforts to use hydrogen as fuel.