This should not be difficult at all.
The Interview can send a text message to the Recruiter.
If he is a little lazy kinds then need not to worry, he can try to give him a call to let him know the Good/Bad news.
if the above two do not work, Assuming that they both are very good friends as they work in the same LOB.
The interview can also call him over for a drink and whisper it in his ears, you see.
If all these standard notifications do not work then please try to suggest the below workaround to the customers:
--Having another Status after Interview Status with a Label, lets say "Selected Candidates".
--In this status, only the selected candidates should be placed and a Status Trigger Email can be set in the "Edit Applicant Status Configuration"
-- So when ever a new candidate comes into this Status then an email will trigger to respective Recipients.
Or you may choose any other workaround of your choice.
I am sorry to say that there is no other Designed way of notifying the recruiters, so you can choose any of the above methods as you please.