override 'Edit own content' using taxonomy access
Ok, I've found a way around it. I'm using the Workbench Access module.

This module, which can be used as a stand alone module, allows you to use taxonomy terms as sections you can set on any node and then you need to assign the roles (or particular users) who can update nodes with these terms/sections. In conjunction with the taxonomy access control module I found that you must at least set the global default for that role to 'view'. If you don't, the users of that particular role won't have update AND view access which is not what I wanted. They can see what they've created but they can't change it anymore after they saved it or after a certain taxonomy term has been set, by themselves or automatically through rules. 

Hope that helps others as well!
Cheers!