It is not the law that an accused must shoulder some of the burden of proof that the breathalyser was not functioning properly; see Regina v. Proudlock 1978 CanLII 15 (SCC),  1 S.C.R 525, 91 D.L.R. (3d) 449, 43 C.C.C. (2d) 321 and Regina v. Gibson,  B.C.J. No. 2242 (B.C.Co.Ct.)
"The most advanced legal research software ever built."
The above passage should not be considered legal advice. Reliable answers to complex legal questions require comprehensive research memos. To learn more visit www.alexi.com.