The situation is something like this. You are doing an onsite interview, consisting of 4 or 5 interviews. Some of these are technical, and some of these are behavioral.
Say you completely bomb a critical interview early in the day - a technical one, and you know with certainty (whether because the recruiter has said this is one you must pass or from what you know of past experience) you won't get the job.
Should you continue with the rest of the interviews? Is it considered rude to let the company know you won't continue the onsite to the end?