little troubling how? Really not that much more troubling than your neighbor saying it is his mower now. May be bad example.
But for this scenario, the museum should have done an inventory and told the police the bag was part of the museum and should be returned to the museum. If there would have been conflict from police, museum should have asked for backup from NASA on talking to police. I would hope that NASA would schedule asking museums if the items were still being shown or needed repair or would be better returned to NASA. NASA cared enough to try to get it back.