From what I've read, it seems like it's not likely.  What I think is happening is that different standards of recovered are used and some people have moments where they meet that standard, but then exert themselves and their body fails that test.  They were still infected the entire time, just not necessarily infected in 100% of their body. South Korea has been incredibly slow to clear patients as recovered because they do nose testing.  And there has not been a single reinfection case in South Korea to my knowledge.