Steps to reproduce:

1. Bob delegated Alice and gave permissions to his calendar
2. Alice subscribed to Bobs calendar
3. Alice in behalf of Bob create an appointment without an attendee - Bob is the organizer.
4. Alice opens the event edit dialog and sees herself as an organizer (and can't modify the organizer).

Note, this is important in step 3. to first select the event calendar in Summary tab, then see in Participants tab that Bob's identity is selected. It works correct if you first goto Participants switch to Bob's identity and then choose Calendar in Summary.

Expected behavior in step 4. is to see Bob as the organizer and the field should be editable.