You could do something like this with conditional skip patterns I think. For each block they could be skipped to a different copy of the second question--one copy for those who made an error and one copy for those who did not. Similarly, each of these two copies could be followed by two copies of the third question. Only those who make the error on the first are sent to the second question where, if they make and error, they will be sent to the version of the third question where, if they make an error, they will be skipped out of the session. Take a look at the section on "skipping" in the user's guide and let me know if you have any trouble with it.