Whether the causation element standard under the False Claims Act is proximate cause, requiring both that the harm was foreseeable and that the false statement or fraudulent conduct was a substantial factor in causing the harm, or is the standard 'but for' causation based solely on foreseeability?

QUESTION PRESENTED Whether the causation element standard under the False Claims Act is proximate cause, requiring both that the harm was foreseeable and that the false statement or fraudulent conduct was a substantial factor in causing the harm, or is the standard “but for” causation based solely on foreseeability?