Edward didn't tell Torres the location of the observatory when he was in prison but somehow Torres knows where the observatory is in the final sequence.
In the present-day setting during the game one of the computers you hack shows Desmond Miles' ancestors through his mother and father. This report indicates that the first playable ancestor, Altair Ibn La-Ahad, comes from his mother's side. It shows the second one, Ezio Auditore Da Firenze, on his father's side. This contradicts the original statements made by Ezio and his uncle, Mario Auditore, in Assassin's Creed II that they were indeed descendants of Altair. This was either a mistake in writing or a change to the canon of the series.