41 C.F.R. § 109-38.403-3

Exceptions to § 109-38.403-2 of this subpart are as follows:

(a) As a result of the negligent or willful act of a party other than the organization or its employee, and the responsible party can be determined; or

(b) As a result of mechanical failure and the employee was not otherwise negligent. Proof of the failure must be provided; or

(c) As a result of normal wear comparable to similar vehicles.