This is a straightforward bug and it's obvious within secs of checking.
In ListSortUI class:
private void prepareForChange(ModelChange change) there is a call to modelSelection.insertIndexInterval(change.startModelIndex, change.endModelIndex, true);
The 2nd arg should be a length rather than an end index.
The same bug exists in JTable.SortManager.cacheSelection. I reported to Oracle, but I couldn't get Oracle to fix it.