D.C. Code § 8-1445
There shall be no liability under § 8-1442 for a person otherwise liable who can establish by a preponderance of the evidence that the costs resulting from their acts or omissions were caused solely by:
(3) An act or omission of a third party other than an employee or agent of the defendant, or other than one whose act or omission occurs in connection with a contractual relationship, existing directly or indirectly, with the defendant, if the defendant establishes by a preponderance of the evidence that the defendant:
Mar. 14, 2007, D.C. Law 16-262, § 305, 54 DCR 794
Mar. 25, 2009, D.C. Law 17-353, § 157(d), 56 DCR 1117
D.C. Law 17-353 validated a previously made technical correction.
This section is referenced in § 8-1442.