What is the issue with the HTML Standard?
In the inner navigate event firing algorithm, at the step of waiting for all of promisesList, in the event of a failure, the event's interception state will still be "intercepted". The steps in the rejection handler do not change the event state before calling the finish event given false steps and the first assertion will then fail (Assert: event's interception state is not "intercepted" or "finished".). Either the state needs to be updated before doing this or the assertion should be skipped when finishing the event given false.