I have answered the question about the odd end of day volume and this was my reply...

I was told that those trades are prints by market makers. They trade through the day and take an average of trade prices and print as a single average priced trade.  I could see that as being true.

I also believe that there are crosses.  Where people move shares from one brokerage account to another.  When I was a broker rather then go though the long process of cert delivery we would cross shares from another firm to that same client at our firm.  As you said there is no way the bid was hit with these trade because it wold have dropped hard and it did not.