User:SOTO/Forum Archive/The Panopticon/@comment-9435571-20130713021912/@comment-9435571-20130713101423
Well, I agree it might be a grey area, but in this case the reference to a major historical event is IMHO too obvious to not assume it's about Julius Caesar.
If it was about "Hitler entering Poland" would we assume that it might be about Alois Hitler going shopping to Krakow and not about the start of WW2 and Adolf Hitler? If a mention is made of Shakespeare being a literary genius without specifying that it's about William, would we assume that it might also mean Clive Shakespeare and therefore is ambiguous? If the Doctor mentions Newton or Columbus, can't we really assume it's about Isaac and Christopher? Hell, even "Julius Caesar" might be ambiguous, since in "100 BC" we meet Gaius Julius Caesar the Elder.
A mention of "Caesar crossing the Rubicon" in the episode assumes that the viewers know who they mean
I think references to such major historical events are a bit more obvious than references to literature, comics and movies you mentioned.