A mistake of law in relation to consent to contract constitutes a mistake resulting in voidable consent only when it arises from:

1. (1) A misapprehension of the law by all parties, all supposing that they knew and understood it and all making substantially the same mistake as to the law; or
2. (2) A misapprehension of the law by one party of which the others are aware at the time of contracting, but which they do not rectify.

Source: CivC 1877, § 889; CL 1887, § 3513; RCivC 1903, § 1207; RC 1919, § 822; SDC 1939, § 10.0313.