Fico and Down payment are not the only two factors in the equation, just because he is a doctor doesn't mean he should get a loan if his house payment and debt service is 2/3 of his income.
Temeculaguy is right. In order to get a jumbo loan, you need all 3 factors:
1- Good credit score
2- At least 20% down payment
3- Housing expense to be "inline" with income
It's likely that the loan amount that the doctor was trying to get is "out of line" with his income.