I have been rfe-reading OotP (yet again) and noticed that Trelawney started working at Hogwarts (nearly) 16 years previously (ch 15), but Snape only had taught for 14 years. This seems a little strange when Snape was eavesdropping when trelawny had her interview and gave the now infamous prophecy because he was also about to be interviewed.
Why is it that there is at least 1 year, possibly 2 between the times when Snape was up for interview and when he was appointed potions master? i know he was after the dada job, but we've had no explanation as yet about the time difference. Does anyone think there is a real reason for this or just a mistake?
PS. Aberforth better hurry up and make his appearance soon - he's running out of books to appear in........