The astronauts only need seven hours of "free-flight time" to perform the end-of-mission maneuvers and Starliner currently has enough helium for 70 hours of free-flight time, Boeing said.
From a business point of view, I don't think lying about this is in their best interest. If they lie to the FAA about their passenger planes, maybe they get an investigation and a fine. If they lie to NASA about the safety of Starliner, they lose their only customer for it.