Actions stop default behaviour if they don't trigger

If an action type is stoppable (such as clicking on a link), and the user has any action registered with that type as a trigger, the event will be halted if the action doesn't trigger.

So if the user has an action that's triggered on URL click, and the action has a condition that checks for "google.com" in the URL, the user will ONLY be able to open URLs where that condition matches, regardless of the "stop" setting of the individual action.