Basically the title. If the social status was against black people as the norm, could slavers forcibly take this person again? Could a freed former slave defend themselves legally if this were to happen?
This was essentially what happened to Solomon Northrup, who was a free black man living in New York. He was kidnapped and spent 12 years as a slave in Louisiana before finally re-gaining his freedom through the intervention of some of his friends.
The kidnapping was illegal, but because a black man could not testify against a white man in court, the slave trader who sold him was charged but acquitted due to lack of evidence. The men who kidnapped him were also not charged, mainly due to a confusion over which region had jurisdiction.
Northrup wrote a memoir, 12 Years A Slave that was recently made into a movie of the same name. I have not seen the movie so I can't comment on its historical accuracy, but supposedly it's very good (and won the Best Picture Oscar).
So, at least for one man, your scenario was very possible, and while technically the whole thing was illegal, no one was punished.
Myself and /u/sowser answered a similar question recently here.
The short answer is that slaves who gained their freedom had to rely on either a court deed that stated they were free (and that people would respect that document, which occasionally they didn't) or on the good will of their neighbors and anti-slavery advocates to protect them should they be captured and shipped south.