If the scammers wanted, they *could* replicate that too ...
You hang up, scammers keep you on the line, play you a fake dial tone, relay whatever digits you dial for your friend as an outbound call on another of their lines, patch the two calls together, let you speak to your mate, once you've convinced yourself the line is OK and hang up again, they *still* keep you on the line and play you more fake dial tone, then you dial the C/C number, they play you some fake ring tone and they "answer".
As described earlier, the recall button (or a different line, or mobile) really is your friend (does any of this apply in NZ?)