Previous phone call recipient could hear me in my next call

Strongbow

1) I called person A
2) Person A switched to another call
3) Call dropped for Person A
4) I placed new call to Person B
5) Person A ended their call with another person (I think my call was still on hold)
6) Person A could hear me talking to Person B. I could not hear them, nor could they hear Person B

This seems like a security issue. Someone could hear my phone call. I'm a bit disturbed by this. Is this expected?

de0u

Strongbow Maybe run the experiment again while taking notes? I suspect that what happened in step 3 was not the call dropping in the sense of the carrier and the phone agreeing the call was over.