R v Lopez-Restrepo, 2018 ONCA 887 (Trotter):

[21] On this appeal, Mr. Tsegaye attempts to withdraw his guilty plea, claiming that it was not fully informed. In an affidavit he contends that he was not advised by his trial counsel (not Mr. Sheppard) that his guilty plea would prevent him from appealing the s. 11(b) ruling. He said, “that would have been a factor that I would have considered in deciding whether to change my plea to guilty.” Mr. Tsegaye’s trial counsel swore an affidavit in which he said that he was not aware that a guilty plea would preclude an appeal of the s. 11(b) ruling.4

[22] Given my conclusion on the s. 11(b) issue, it is unnecessary to decide whether Mr. Tsegaye’s situation is distinguishable from Faulkner and whether he should be permitted to withdraw his guilty plea. Nevertheless, I make the following observations which may assist in future cases.

[23] It is well-known that a guilty plea may have profound and far-reaching consequences. A guilty plea involves a broad waiver, sometimes extending beyond an admission of criminal responsibility. In R. v. T.(R.) (1992), 10 O.R. (3d) 514 (C.A.), Doherty J.A. said, at p. 519:

A guilty plea is a formal admission of guilt. It also constitutes a waiver of both the accused’s right to require the Crown to prove its case beyond a reasonable doubt and the related procedural safeguards, some of which are constitutionally protected: Korponay v. Canada (Attorney General), [1982] 1 S.C.R. 41 at p. 49, 65 C.C.C. (2d) 65 at p. 74; Brady v. United States, 397 U.S. 742 (1970), at p. 748, Fitzgerald, The Guilty Plea and Summary Justice (1990) at pp. 192-203. [Emphasis added.]
See also R. v. Parris, 2013 ONCA 515, at para. 121. The constitutionally protected procedural safeguards that are waived include the right to make constitutional claims at trial, as well as the ability to appeal unsuccessful constitutional challenges that were made (including rulings under s. 8 of the Charter (Fegan) and s. 11(b) (Faulkner)).

[24] Because of the broad scope of this waiver, a cautious approach is warranted when an accused person expresses the intention to plead guilty following the dismissal of pre-trial applications, constitutional or otherwise. In these circumstances, the trial judge may wish to enlarge the plea comprehension inquiry under s. 606(1.1) of the Criminal Code to determine whether the accused person understands that, by pleading guilty, he or she will forfeit the right to appeal all previous rulings associated with the case. The inquiry need not be extensive. It may only involve an additional question or two. However, it will ensure that the plea is truly informed, preventing misunderstandings down the road.

[25] Moreover, there is a way to preserve a right to appeal short of having a full-blown trial. In Faulkner, Watt J.A. commended the procedure discussed in Fegan, whereby an accused person pleads not guilty, accepts the case for the Crown (perhaps based on an Agreed Statement of Facts), and calls no defence evidence. A finding of guilt inevitably follows. As Watt J.A. said in Faulkner, at para. 92: “This procedure would preserve the accused’s right of appeal against conviction on the real issue in dispute without imposing the additional burden of setting aside the guilty plea.”

[26] This procedure is utilized regularly in Ontario. With appropriate safeguards, it is an efficient method of dealing with cases in which Charter issues play a crucial, if not determinative, role in a prosecution: see R. v. Tran, 2017 ONCA 329; R. v. G. (D.M.), 2011 ONCA 343; and R. v. P. (R.), 2013 ONCA 53. See also the helpful discussion of this issue in Michael Shortt, “Preserving Appeal Rights When Your Client’s Only Defence is a (Failed) Charter Motion” (2018), 65 C.L.Q. 443.

[27] This procedure is not without its potential hazards. Before going down this path, a trial judge should engage in an exercise approximating a plea-comprehension inquiry to confirm that the accused person understands precisely what is at stake by participating in this procedure: P. (R.), at para. 60.