I have followed closely the events of the SNC Lavalin affair with some interest. This is my perspective on the matter based upon my understanding of constitutional law.
Under Canadian law, the Attorney General does not have complete autonomy with respect to the exercise of her prosecutorial discretion. It is entirely appropriate for Trudeau to have removed her from her position, and to appoint an Attorney General who is willing to stay the proceedings against SNC Lavalin and negotiate a deferred prosecution agreement with the company.
The legal foundation that supports the notion that the government should not politically interfere with the Attorney General’s prosecutorial discretion stems from the common law, in particular the Supreme Court of Canada:
Krieger v. Law Society of Alberta  3 SCR 372
The Supreme Court of Canada has ruled squarely on the issue in Krieger:
“A decision of the Attorney General within the authority delegated by the sovereign is not subject to interference by other arms of government. An exercise of prosecutorial discretion will, therefore, be treated with deference by the courts and by other members of the executive, as well as statutory bodies like provincial law societies. Prosecutorial discretion will not be reviewable except in cases of flagrant impropriety.”
JWR, through her testimony to the committee expressed clearly and credibly that she was put under pressure by the executive branch for a four month period and that they were advocating strongly that she seek outside counsel to review the basis for her decision not to direct the DPP to enter into negotiations with SNC Lavalin on the criminal proceeding. Her evidence is that she was removed from her position as AG as a result of her decision making which should be not be subject to interference by the executive branch.
The executive branch, through the Prime Minister, has said that they felt that they were simply raising important policy issues and attempting to persuade the AG to change her mind, acting at all times in the interest of Canadians.
It is important to note that Krieger, supra, does not provide complete autonomy to the Attorney General. The AG’s decisions are subject to review in cases of “flagrant impropriety.” If the AG is acting beyond the scope of his/her office as protected by constitutional principle, the justification for prosecutorial deference evaporates (Krieger, supra, para 49).
Furthermore, the AG is invited to Cabinet by the Prime Minister, the democratically elected leader of the executive branch. The Prime Minister does have complete autonomy with respect to who serves in Cabinet. If the Prime Minister feels that the AG is not exercising appropriate judgement and acting within the public interest it is well within his/her constitutionally granted powers to remove the AG from their position.
Ian Scott had served as Attorney General under David Peterson and had studied the potential for the executive branch and the AG to come into conflict with one another. The duty to avoid partisan considerations rests with the AG: “The Attorney General occupies a unique position in Canadian law. While both an elected member of the Legislature and a member of the Executive, he or she is also the Chief Law Officer of the Crown, with an independent responsibility to sustain and defend the Constitution and the rule of law. This unique position imposes a duty on the Attorney General to consider, objectively and independently of partisan considerations, what actions must be taken to uphold the rule of law.”
The Hon. Ian G. Scott, “Law, Policy and the Role of the Attorney General: Constancy and Change in the 1980s” (1989) 39 U.T.L.J. 109 at 122:
Consider Mr. Scott’s comments, which are completely on point today:
Of importance to this matter is that it is appropriate for the Attorney General to consult regularly with the Executive branch. It is the AG’s duty to listen to these consultations and determine which are appropriate for consideration. It is not incumbent on the members of the executive branch to make that determination. In other words the Prime Minister is at liberty to say “If you prosecute we could lose the election.” It is the duty of the Attorney General to determine whether to consider that in his/her decision making process. There is no affront to the rule of law to have Cabinet attempt to persuade the AG based on political considerations – it is a natural result of the dual role of the AG based on Canadian traditions.
The question that remains unanswered in the SNC Lavalin affair is why the AG refused to stay the prosecution of SNC Lavalin and enter into negotiations. It was entirely legal for her to do so. There was nothing unethical or untoward about the process, which in fact is a court supervised process that allows for judicial decision making and procedural fairness components. None of the existing board members or persons involved in the criminal case remain in the employ of the company. The former AG has given no juristic reason for refusing to exercise her discretion.
Based on her testimony, it appears that JWR believed that it was “inappropriate” for the government to intrude on her decision making and that that somehow compromised the rule of law. Perhaps she believed that she had complete autonomy in the decision in all respects. That is simply not the case, and if the executive was of the opinion that it was in the public interest to stay proceedings against SNC Lavalin then it was incumbent on Ms. Wilson Raybould to either issue the directive in accordance with the Prime Minister’s wishes or resign.
It was further inappropriate of her to remain and place the Office of the Attorney General in conflict with Cabinet. The Attorney General is subject to judicial review, and serves at the request of the Prime Minister. The Office should rightly defer to the public policy position of the elected Prime Minister and Cabinet, provided that they are acting in the public interest and upholding the rule of law. The Attorney General is not a sovereign autonomous office that can override the executive branch for reasons unknown. In fact, Democracy demands exactly the opposite.