Nothing to report yet, though thank you for your data log! It's a complicated interplay between a few different factors, including the inherent (and maybe slightly incorrect) behavior of the ADS-B ground stations.
If you need information on the subject of ADS-B traffic ghost, google it. "ADS-B traffic ghost" "http://media.blackhat.com/bh-us-12/Briefings/Costin/BH_US_12_Costin_Ghosts_In_Air_WP.pdf" Lots of information on the subject.