necessary to give effect to the defence: Cinous, at paras. 65, 82;
Cairney, at para. 21; R. v. Mayuran,  2 S.C.R. 162, 
S.C.J. No. 31, 2012 SCC 31, at para. 21.
 Where the defence in issue is the statutory partial defence of
provocation, the air of reality standard must be satisfied for both
the objective and subjective components of the defence: Pappas, at
para. 21. In other words, the test is whether a reasonable jury,
properly instructed, could draw the inferences necessary to have
a reasonable doubt whether the accused was guilty of murder, on
the basis of the defence of provocation: Pappas, at para. 21; Tran,
at para. 41; Mayuran, at para. 21; Cairney, at para. 21.
 It is uncontroversial that the air of reality standard may
be met by the introduction of direct evidence or circumstantial
evidence. Where the evidence is circumstantial, however, this
requires inferences to be drawn to establish the elements of the
defence. In such cases, a trial judge may engage in a limited
weighing of the evidence to determine whether the essential elements of the defence can reasonably be inferred from the evidence. But in this limited weighing exercise, the judge must
not make findings of credibility or reliability, or findings of fact
or draw determinate factual inferences: Cinous, at paras. 53-54,
87-91; Pappas, at paras. 22-25.
 Sometimes counsel may ask a trial judge to instruct a jury
on a defence that is inconsistent with the defence advanced at
trial. The air of reality test controls whether a defence not specifically advanced at trial should nonetheless be left to the jury.
The test requires examination and assessment of the whole of
the evidence, as well as the conduct of the trial as a whole.
Incompatibility of the proposed defence with the primary
defence does not, without more, mean that the proposed defence
lacks an air of reality: R. v. Gauthier,  2 S.C.R. 403, 
S.C.J. No. 32, 2013 SCC 32, at paras. 32, 34; R. v. Graveline,
 1 S.C.R. 609,  S.C.J. No. 16, 2006 SCC 16, at para.
10; R. v. Doucette,  O.J. No. 4523, 2015 ONCA 583, 328
C.C.C. (3d) 211, at para. 30.
 The nature of the primary defence advanced may factor
into a consideration of whether there is an “air of reality” to
a defence which conflicts with the primary defence: Doucette, at
para. 31; R. v. Phillips,  O.J. No. 5022, 2017 ONCA 752, 355
C.C.C. (3d) 141, at para. 148. Incompatibility of the defences may
leave evidentiary gaps on essential elements of the proposed
defence that cannot be overcome.
The principles applied
 I would give effect to this ground of appeal.