Hi , in this case why do they need so complicated procedures such as RQ to prove residency
This is a more complicated subject than it might, on the surface, seem.
When IRCC apprehends the applicant's information is subject to question, it is IRCC's mandatory obligation to require the applicant affirmatively prove his or her case. With very narrow exceptions, the Minister (IRCC) does not have any legal authority to grant citizenship UNLESS a proper application has been made which establishes the applicant's qualification for the grant of citizenship. Thus, if there is a question, IRCC CANNOT, not legally, grant citizenship unless and until the question is resolved in favour of the applicant.
The burden of proof is on the applicant. An omniscient power, deity or AI or whatever, may know for certain an applicant was present in Canada 1200, 1300, even 1800 days within the relevant five years, BUT IRCC CANNOT, not legally, grant this individual citizenship unless and until the individual PROVES he or she was actually physically present in Canada at least 1095 days during the relevant five years.
As long as IRCC's review of the information indicates the applicant's application sufficiently documents facts which show the applicant is qualified for the grant of citizenship, IRCC basically, more or less, grants citizenship based on the information provided by the applicant. Of course IRCC employs multiple methods to cross-check (verify) the applicant's information, at least sufficiently so that IRCC is satisfied there is no reason to question or doubt, let alone challenge, the information the applicant has provided. (Allowing for typical minor mistakes.)
BUT when IRCC comes across reasons to question what the applicant has submitted, IRCC is obligated by law to NOT grant citizenship. Again, the burden of proof is on the applicant. At the same time, Canada is a rule of law country which embraces due process or "fair procedure" requirements, so applicants must be given a fair opportunity to respond, an opportunity to make their case, to prove they are in fact qualified.
That is what RQ really is. It is first a notice to the applicant that IRCC is not satisfied the applicant has sufficiently established qualification for citizenship, and it is secondly a rather detailed enumeration of the information the applicant needs to submit in order to meet the burden of proving qualification. It is comparable to a fairness letter in other contexts. It is notice to the applicant that the information provided so far does not meet the burden of proof, and an opportunity for the applicant to further respond by submitting information and evidence (mostly documents) which will meet the burden of proof.
As I have oft noted, IRCC primarily uses information about the applicant and related, collateral information, to check the veracity of the applicant's information. For example, while IRCC may sometimes (such as in a RQ case referral to a Citizenship Judge) build a calculation of travel history based on information like the individual's CBSA travel history, this is mostly about explaining what is wrong about the applicant's version . . . and, moreover, this is an explanation presented to the CJ NOT to the applicant (applicant is merely issued the RQ and not given an explanation about what or why IRCC is questioning the applicant's case).
The applicant is merely given the opportunity to more thoroughly document his or her version, by being given the RQ which solicits specific information and evidence (mostly documents) which are relevant to making a factual determination . . . AND IT IS IMPORTANT to understand, that factual determination is NOT about recalculating how much the applicant was present or absent, BUT IS ABOUT DETERMINING IF THE APPLICANT HAS MET THE
BURDEN OF PROOF, about ascertaining if the applicant's information and evidence PROVES THE APPLICANT WAS PRESENT AT LEAST 1095 DAYS IN THE ELIGIBILITY PERIOD.
Perhaps the most salient example illustrating what this means is the case in which the applicant submitted school records to show when her children were in school in Canada, to corroborate her other information and evidence about when she was present in Canada. Problem was the school records showed the children were in school during a period of time (a couple or so weeks) when the applicant had reported she and the children were abroad. On its face this might appear to show the applicant should get credit for more days in Canada. The Citizenship Judge, HOWEVER, did NOT give the applicant more credit for that period BUT RATHER (as apparently the Minister had urged in the FPT referral to the CJ, and explicitly argued in the Federal Court) considered this to show the applicant's version was NOT accurate, NOT credible, and thus this was part of the reasoning for concluding the applicant failed to meet her burden of proof resulting in the application being denied.
In other words, evidence which tended to indicate the applicant may have been IN CANADA a period of time
IN ADDITION to the times she reported being in Canada, was used as a reason to conclude the applicant failed to prove she was in Canada enough to meet the qualifications. (Because the evidence showed, according to the Minister and the CJ, the applicant's accounting was not sufficiently credible to prove when she was in Canada.)
Personally I thought that reasoning was erroneous and perhaps even unreasonable. The format of the school records suggested the attendance record probably indicated a period of time when the children were enrolled and not necessarily about when they were physically present on given days, so to my perspective the records did not contradict, at least not necessarily so, the applicant's report about a couple or so weeks abroad during that period. For purposes of appeal, the difference between a decision which is erroneous and one that is unreasonable is huge. The Federal Court can conclude the CJ's decision was erroneous but within a range reasonable people might have differing views, in which event the CJ's decision MUST be upheld. ONLY IF the CJ's decision is found to be UNREASONABLE can the Federal Court rule it invalid. That is, a WRONG decision is NOT enough to get a decision reversed on appeal (to be clear, this is a well-worn standard and is perhaps one of the most commonly employed principles in appellate review).