i know someone who has a facebook page and saw other shomer shabbos peoples names having a status update during shabbos hours. it said mr pipik and mr smith are now friends and the time was somewher in the afternoon on saturday.
mr pipik is the jewish person and mr smith is not. so i asked someone to explain this to me and was told that mr pipik may have requested to be a facebook friend with mr smith on thursday and mr smith first accepted it saturday afternoon. not that mr pipik
g-d forbid was on facebook during shabbos.
sooooooo you never know how the mechanics work. perhaps there was a lag in the posting as well.
i personally have gotten text messages to my cell phone many hours after sent if there was a problem with the reception or carrier.