making that argument, the Crown did not seek to put the
accused in jeopardy for a second time. Rather, the Crown argues
that the error relied on by the accused caused no substantial
wrong or miscarriage of justice, because on a proper application
of the law, provocation should never have been left with the jury
in the first place. The distinction between the two positions
lies in the difference between an argument demonstrating the
harmlessness of an error made at trial, and an argument said to
justify the retrial of an acquitted accused: see, e.g., R. v. Flegel,
 O.J. No. 1602, 196 C.C.C. (3d) 146 (C.A.); and R. v. Tremblay,  J.Q. no 4625, 2007 QCCA 696, 50 C.R. (6th) 349.
 There is, however, a substantial body of case law dealing
with Crown appeals that argues strongly against the Crown
being allowed to advance this ground of appeal. I begin with
R. v. Wexler,  S.C.R. 350,  S.C.J. No. 22. In Wexler,
the accused was charged with murder. At trial, the Crown
argued that he had intentionally shot the deceased. The accused
testified that the shooting was accidental. The jury acquitted
and the Crown appealed.
 On appeal, the Crown argued that the trial judge had
erred in law in failing to put a second factual and legal basis for
liability to the jury. The Crown at trial had not argued that this
alternative theory should be put to jury. The Quebec Court
of Appeal allowed the Crown appeal and ordered a new trial.
The Supreme Court of Canada unanimously allowed the further
appeal and restored the acquittal.
 There are three judgments in Wexler. All stand firmly
against the Crown’s use of its right of appeal to secure a retrial
based on the theory or legal argument not advanced at the first
 Crocket J. put it this way, at pp. 357-58 S.C.R.:
To subject him [the accused] now, after he has been put in jeopardy, taken
the stand in his own behalf and been acquitted on that indictment, to a new
trial thereon on the ground that he might have been convicted of manslaughter if the Crown counsel had not failed to put this feature of the case
forward on the trial would, it seems to me with all respect, be such a manifest injustice as Parliament could not well be deemed to have intended when
it enacted this drastic amendment to the Criminal Code.2
 Wexler has been applied in the Supreme Court in cases in
which the Crown has sought to advance on appeal a different
legal or factual basis for conviction than was advanced at trial:
see R. v. Savard,  S.C.R. 20,  S.C.J. No. 42, at p. 37
2 The amendment created the Crown’s right of appeal from an acquittal.