Switching off the computer will have destroyed the Eraser log, as it is held in memory until Eraser exits normally. That said, in your position I would have done what you did to try and save some files at least.
If the files no longer appear in Explorer, they are almost certainly gone. You can use a file recovery program such as Recuva, to find out whether anything recoverable remains.
After running eraser it is assumed that the deleted files will be shown in Recuva ?
Shutting down the computer will make some files corrupted ?
There is some order to delete files? (By sectors, alphabetically...)
If a file is deleted, it will show up in Recuva. If it is erased, under normal conditions it will not show up in Recuva. Your switch-off created abnormal conditions, and therefore it made sense to see if anything was recoverable, even if it was not visible in Explorer in the normal way.
Switching off without shutting down properly can certainly corrupt files, but it does not happen invariably. Again, Recuva may help.
I don't know what order Eraser deletes files in, but would assume that it is in the order in which the file names appear in the task definition, which is the order in which they were added to the task.