[bairy]

Error code 28 means no more space left. Either the hard drive ran out of space or your allowed disk space maxed itself.
If you really have 562k images, and I believe you do, then that's not really a surprise as the script creates a new table with all the images in it. I have 1300 images and takes up about 170k. So multiplying it up there's probably a table size of 70mb or so.

However it obviously managed to get some images in at least.

The duplicate/dealt with message comes up because:
Lets say you have one image and it's been linked in 2 posts. There's no point scanning the same image twice since one scan will tell us if it's valid. Therefore it's scanned once and if the image comes up again it's counted as 'duplicate' or 'dealt with' (they mean the same thing in this case).
Another reason is if you resume a scan (not restart it). As it will already have scanned some of the images and they'll be classed as "dealt with".
If you have a lot of images saying that then it could be because you're doing another scan but not from the start, or it could be related to the error 28, depending what got inserted and what didn't.