When the astronaut finished walking on the moon he entered the Lunar Module where moon dust would have settled. The Lunar Module did not return to earth. It was released to crash into the moon or the sun. If we accept the Command Module as a likely place for lunar dust, we should also accept any equipment from inside the crew spaces of the Command Module, equipment which might now be displayed separate from the Command Module itself.
Soviet craft Luna 16, Luna 20 and Luna 24 also returned to earth with lunar samples.