Standard User cannot edit un-assigned project/task/ticket.

I created a teammember entry for myself for a specific task. I then un-assigned this task from myself because I was no longer going to be responsible. However, responsibility has now changed again but I cannot edit the task under team-members because I am not authorised to edit the entry (presumably because I am not the blank user currently assigned).

Not sure if this is a bug or design intention, but again is counter intuitive. I understand I should not be able to "steal" another users task, but I should be able to assume control of an unallocated task.

I cannot delete the task either for similar reasons, so currently there are two instances of the task set up, one assigned to a blank teammember and one assigned to myself.