2 steps workflow engine: inconsistent workflow step wizard

Setup with John (ACME) a complex workflow on the Activities section. Then I initated a new publishing workflow (publication > publish Activites).

By default (screenshot1) I have a single step workflow (I setup a complex workflow!), if I cancel the action button, the second step workflow appears. If I launch the workflow, the engine stays open. I can add some comments. And then I can relaunch the second step workflow (and then you are not sure if the workflow was launched twice or not).

Shouldn't the engine freezed with a "please waiting msg" as soon as the action button is hit by the user + the engine automatically closed when the workflow was correctly queued?