I strongly doubt your call was "hijacked." My best guess is you accidentally hit a key (or a combination of keys) that did an automatic call back to the last caller. Like *69 for instance? Or maybe your phone has a dedicated key for that?
And does your phone have a call history itself? If so, can you scroll back and see the call made from your phone to the telemarketer number? If you see that call in your phone's history then the problem is with the phone (or its operator), and not Google or the OBi device.