Battlestar Galactica apparently exists in the world of Dollhouse, but only as a show. That would explain calling someone a Cylon.
Sharing actors is nothing new. Summer Glau is in Dollhouse, Terminator: The Sarah Connor Chronicles and Firefly / Serenity (along with Alan Tudyk who also appeared in Dollhouse). This does not suggest that they are all in the same 'verse. Adelle DeWitt (Olivia Williams) did not just have her husband Bruce Willis die, and Patton Oswalt's presence does not mean this is stand-up comedy. It's crazy how many of these people like to work together and get to on such fun (albeit usually short-lived) shows.
BSG is controlled by The Sci-Fi Channel (someone else can edit that) and Dollhouse was run by FOX. That's a bureaucratic problem with them existing in the same uiniverse, minus all the logistical.