To reproduce the bug:

1. in a course create a choice Enabling the Limit of Response.
2. enter two or three choices, limiting each one(say, 1 slot available for each choice)
3. now login as an admin (taking care this user does not has role in the above course) and complete the choice. The selected choice appears as "Complete" but looking at the answers, the admin user does not appear in the list of people who made a choice..

Giving the user a role, it appears in the user's choice list.