How to cleanup after failed rsync?
Tell rsync to delete files not on the source, with --delete-during or --delete-after. Be careful and use this option only if you don't have legitimate files on the target that aren't there on the source.
See man rsync.
Of course, you could always manually delete the files you detected with diff...
I do it using
find -type f -iname ".*.*.??????" -ls
for test and
find -type f -iname ".*.*.??????" -delete
for clear