To reproduce:

1. Start inline editing on a cell (do not close/submit)
2. Reorder some rows by dragging them.
3. Result:
   
   • The inline edit is submitted to the server in the _tidy call of the editor.edit function.
   • RowReorder doesn't wait for the submitComplete callback in _tidy, and calls editor.multiSet.
   • RowReorder call editor.submit, but since this.s.processing is still true, it returns and does nothing.
   • RowReorder updates the sequence numbers as shown in the table.
   • The first submit of the inline edit returns, and editor thinks it is done processing. This sets the sequence number of the row we inline-edited to the value the server thinks is correct.
   • Now, the sequence numbers are mixed up.

Probably, the multiSet and/or submit calls at line 510 of dataTables.rowReorder.js should wait while editor is tidying up any remaining edits, but I don't know whether this is possible in the current framework.