A month ago I remembered this possibility too late to actually try it. Was on a sorta-MR from DFW-LAX-ATL-DFW (not a pure MR as I planned it for miles but chose destinations based on knowing people there I could pay a visit to). My friend in ATL bailed on me the day I was going there from LAX. I just went to a hotel intending to take my planned flight home the next day, and later it occurred to me that I should have just walked a couple of gates down and tried to get back on another plane going back to DFW that night. Argh.
Oh well. Sounds like my chances would have possibly been slim anyway.