Disabling user sorting while keeping default order intact

I want to disable user sorting while force sorting on the first column in ascending order. For whatever reason, I cannot seem to get this to work. Here is a fiddle demonstrating the problem I am seeing:

http://jsfiddle.net/725km1ro/

The only way I have been able to get this to work is thus:

http://jsfiddle.net/awswpxLy/1/

But the table in that case still displays a sort arrow.

So, what am I missing here?