What is the ruling on a husband presenting his wife to a male doctor after a medical error occurred with a female doctor?

It is not permissible for a woman to be treated by a male doctor if she can be treated by a female doctor, whether Muslim or non-Muslim. If there is no Muslim female doctor, then a non-Muslim female doctor, then a Muslim male doctor, then a non-Muslim male doctor. If the female doctor's expertise is insufficient to treat the condition, then it is correct to go to a male doctor who possesses sufficient expertise.