Can he not create a new account for his company, not the developers, and be the one to publish the app? It's not like he has a history to preserve (ratings, reviews, etc).
I imagine he has a contract with the devs so he can get the app in some form (hopefully access to source too) and publish it himself. Of course, publishing to mobile phone stores can be difficult for non technical people, but if that is the case he can request "over the shoulder" assistance with screen sharing so he ends up being the one logging in and doing the actions.
In the iTunesConnect portal, you can assign roles to various parties, including roles that have permissions to publish apps, without having to give the admin's account credentials.
I don't remember if the Play Store has similar features.