This is not suspicious.
When the automated tasks run behind the scenes on Moodle, the actions performed automatically often get attributed to the admin user. That will be what happened here. I expect your quiz is set to submit automatically when time expires.
You can see that 'User2' did not change the response which the student had input and saved.
When the automated tasks run behind the scenes on Moodle, the actions performed automatically often get attributed to the admin user. That will be what happened here. I expect your quiz is set to submit automatically when time expires.
You can see that 'User2' did not change the response which the student had input and saved.