If you start virt-viewer with the --reconnect option, and then get disconnected because another client attached to the same guest, virt-viewer will switch to the black screen that says "Waiting for guest domain to re-start" It stays that way forever, even though the guest domain did not actually shut down. Virt-viewer won't attempt to re-connect until the guest actually does shut down and restart again. It would be nice if virt-viewer could discriminate between a disconnect that was caused by the guest shutting down and those that are not. In the latter case, it could offer a 'Click here to try to reconnect now' option.
come to think of it, it would be nice if this 'click here to reconnect' behavior was standard for all non-shutdown disconnections, even if the --reconnect option was not specified.
Virt-viewer doesn't have the knowledge to implemented the requested behaviour. It has no way of knowing why it got disconnected from the server.