Unable to uncheck the Allow Bidder XML Downloads box on Strategic Sourcing Event

We have the scenario where a buyer accidently flagged the event as Allow Bidder XML Downloads.  They now want to remove that.  Is that possible after an event has been posted?

1. Create a sourcing event, navigate to Sourcing>Create Events>Event Details

2. Click the Event Settings and Options link

3.  Make sure the Create PDF on Event Post is unchecked

4.  Add line item

5.  Make sure the Allow Bidder XML Downloads box is checked

6.  Flag event as Public

7.  Post the event

8.  Edit the event

9. Click the Event Settings and Options link

10.  Notice that the Allow Bidder XML Downloads field is now grayed out, checked and uneditable (even if you select the Create PDF on Event Post<<<which is what was intended)