I recently had some problems calling an external service (related to authorization). When the service was called, I just got a message, that there was an error. No details.
As I had access to the Domino server console, I got a little bit more.
As I had access to the file system of the Domino server, I could open the referenced error-log-0.xml.
As I'm an experienced Web developer, I know how to get to the developer tools of my browser and find network related information (and the browser' console).
A typical citizen developer would have non of this!
Thus, to not frustrate him (or her) and don't make him wait for the IT department again (what Volt is all about), give him more information to help him to fix his problems without coding/admin professionals.
One fast, easy way to start with: Give him access to some logs, where he can find problems and errors with details only of his (or her) app - not everything happening on the server.
For the future discover a way, how he could kind of debug the code parts (including service calls) of the app.