I think you were redirected to yourself then occupied then redirected one last time giving you immunity to occupation/target change/jail
I have thought about this as well but that was night one. Next night I was debbed and it was successfull. Finaly, night 3 I was immune as well, but a message about immunity has appeared AFTER someone tried to occupy me.
Maybe you were redirected to yourself then occupied but then somehow CW barriered? Idk tbh
This seems like the Butler and Drunk interaction, though I think this is more likely to be Sellsword considering the order.
Upon being occupied, you cannot be Debbed.
First thing that happened: CW swapped your target to yourself
Second: Sellsword occupied you.
Third: Drunk tried to deb you
This should not be a bug I think.
(Unless ofc; the game did not have any invokers/drunks)