First, the at fault driver's policy limits may not be the only source of funds available to pay for the damages sustained. IF your friend has his own auto and it is insured, the Uninsured/Underinsured Motorists coverage -- which is typically a part of the auto policy -- would provide a source for additional recovery. Essentially his/her auto insurer would take on the role of the other driver's supplemental liability insurer.
Second, even if the at fault driver's auto insurance policy limits may be low, the driver (and/or car owner) is not necessarily off the hook. He or she may still be personally liable for the full measure of damages -- and most other assets the driver has -- such as a home, car, jewelry, and savings and investment accounts not part of an IRA, 401(k), or similar plans, could be seized after a judgment is obtained.
Third, it would seem given the significant medical bills, your friend may have sustained some permanent injuries or loss of mobility as well as pain and suffering. If that is the case he or she certainly would need a lawyer to get the maximum benefits to which he or she would be entitled. An insurance company doesn't just write a check for the full amount they would be prepared to pay just because an individual without a lawyer asks it to.