Just so I'd have something to compare it with, I checked Bank of Ireland's share price and trading volumes for the same period as I did for Anglo-Irish below. Here is the table.
I'm not sure I can say anything definitive about the movement of Anglo's share price or the trading volumes. What you see is that Anglo is more volatile over that period, but whether that has anything to do with the IL&P deposit is impossible to say. What's not impossible to say is that nearly 50,000,000 Anglo-Irish shares were traded between September 29 and October 10. And, it seems pretty unlikely that all of those who were buying and selling were aware of what was going on.