In 7.3, “stop the action” is documented:
This phrase stops the current rule, stops the rulebook being worked through, and finally stops the action being processed. Example:
This is correct; it doesn’t say anything about the rulebook outcome.
The key point in 19.11:
When a rulebook is followed, what happens is that each of its rules is followed in turn until one of them ends in success or failure
But as the rest of that section explains, the rulebook outcome is a separate matter. Stopping the rulebook without an outcome (rule succeeds / rule fails) takes you to the default outcome, which is often “no outcome”.
This could definitely be explained better. It’s also hard to get right in practice, because for many games, the rulebook outcome of an action is not important. You can write a great deal of Inform without ever worrying about whether your action counts as a success or a failure – you just want to get the right text and behavior out.
“Unsuccessful attempt” rules are one of the cases where it does matter, as you see.