Unintentional assignment of contact tag

Open an item edit dialogue
Select the item type as Waiting and choose a contact
Do not close the window
Select the item type as Inbox/Next

Now the item has assigned the contact tag that was chosen during this operation.
There is no easy way to remove it. You have to change the item type to Waiting, save and then go back to Inbox/Next type.

The contact should be cleared when changing away from Waiting. This should be quick to fix.