Subpanel Field Moves From Last To First Column after Document Create

In custom/modules/Documents/Case_subpanel_documents.php I’ve added an additional column to the documents subpanel for the Cases module.

What is very strange is that after creating a document, the field in the last column shows up as the first column so all the column headings are off. A refresh of the page corrects it. Yet the URL is of course identical. So the page refresh that is caused by creating a new document seems to be doing something wonky.

Anyone have any ideas or seen this before?