In order to do something like this, you would have to have the course manage the quiz internally. This means that all quiz questions presented to the student must be set to not be scored. This separates the quiz from the LMS (or Moodle) tracking so you can allow the course to manage the exam behavior. On the last page of the exam you would place a single LMS scored M/C object and trigger the choices according to how the student performed.
So basically, you have to make sure all your exam questions have the
"Score this question" item
UNCHECKED.

- UNCHECK Question scoring to prevent Moodle tracking.
- mcImage.png (28.26 KiB) Viewed 7225 times
Then, on the last page you would use a single M/C question object (hidden) that IS set to be scored. However, the state of this hidden M/C question would be set based on how the student performed on the NON-SCORED questions. A simple variable could be used to track the consecutive correctness of the answers.
NOTE: When a question is set to not be scored, this DOES NOT mean the correctness of the answer cannot be known. ToolBook still reports this to the course via the
on question answered event. The scored option only governs whether the LMS is sent the score. That is why in this case you would need to turn this feature off so you can perform more advanced evaluation on student performance (e.g.: grading on a curve, etc.).
A typical action for the
on question answered event may look like this for the non-scored questions that the student answers:

- on question answered action for NON-SCORED questions.
- nonScoredQuestionAction.png (31.94 KiB) Viewed 7225 times
You would have to decide how to evaluate the variable on the last page (or summary) of the course. If this is a simple pass/fail exam based on consecutive correctness, then just trigger your hidden M/C question to be correct (pass); otherwise leave it incorrect so Moodle tracks the course as failed.
This should give you a pretty good start.