One of the things lenders do in evaluating the risk of a potential borrower defaulting on a loan is to consider the potential borrower' s credit score. In general, the higher the credit score, the less the risk of default. Yet for mortgage loans, the proportion of defaults is much higher for borrowers with the highest credit scores than for other borrowers.
The statement 'Mortgage lenders are much less likely to consider risk factors other than credit score when evaluating borrowers with the highest credit scores' most helps to resolve the apparent discrepancy in the statements above.