Call a missed call from the lockscreen of iphone.

Since the lockscreen, it is possible to call the person who called us without dialing the unlock code.
Iphone is locked when it should not be able to call without dialing the security code.

For example, a girl in my repertoire calls me, I do not answer because I'm not next to my iphone. My girlfriend take my iphone and saw the name of a girl she does not know, she is very jealous. She called the girl with my iphone by sliding your finger on the contact and the daughter says she does not know.