Just because Fedex didn't do it doesn't mean they shouldn't have.
§ 382.303 Post-accident testing.
(a) As soon as practicable following an occurrence involving a commercial motor vehicle operating on a public road in commerce, each employer shall test for alcohol for each of its surviving drivers:
(1) Who was performing safety-sensitive functions with respect to the vehicle, if the accident involved the loss of human life; or
(2) Who receives a citation within 8 hours of the occurrence under State or local law for a moving traffic violation arising from the accident, if the accident involved:
(i) Bodily injury to any person who, as a result of the injury, immediately receives medical treatment away from the scene of the accident; or
(ii) One or more motor vehicles incurring disabling damage as a result of the accident, requiring the motor vehicle to be transported away from the scene by a tow truck or other motor vehicle.
(b) As soon as practicable following an occurrence involving a commercial motor vehicle operating on a public road in commerce, each employer shall test for controlled substances for each of its surviving drivers:
(1) Who was performing safety-sensitive functions with respect to the vehicle, if the accident involved the loss of human life; or
(2) Who receives a citation within thirty-two hours of the occurrence under State or local law for a moving traffic violation arising from the accident, if the accident involved:
(i) Bodily injury to any person who, as a result of the injury, immediately receives medical treatment away from the scene of the accident; or
(ii) One or more motor vehicles incurring disabling damage as a result of the accident, requiring the motor vehicle to be transported away from the scene by a tow truck or other motor vehicle.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=382.303