I think this is the reference and am not sure that it is applicable in this case as this couple applied for PR together, not that one was sponsored by the other spouse.
http://www.cic.gc.ca/english/resources/manuals/bulletins/2012/ob386.asp
Operational Bulletin 386 - March 2, 2012
Five-year Sponsorship Bar for persons who were sponsored to come to Canada as a spouse or partner
Summary
A regulatory amendment will bar a person who has been sponsored as a spouse or partner, from sponsoring a new spouse or partner for a five-year period.
Issue
The purpose of this Operational Bulletin (OB) is to inform officers of the regulatory amendment to section 130 of the Immigration and Refugee Protection Regulations (IRPR) that bars, for a five-year period, a sponsored spouse or partner from sponsoring a new spouse or partner.
Background
One of the objectives of the Immigration and Refugee Protection Act (IRPA) is to facilitate family reunification. As such, Canadian citizens and permanent residents (PRs) may sponsor their spouse or partner as a Canadian PR. Spousal sponsorship requires an undertaking of financial responsibility for a spouse or partner for three years. If the relationship breaks down, the sponsor remains financially responsible until the end of the three-year undertaking period, irrespective of the causes of the breakdown. As well, a sponsor may not sponsor a subsequent spouse or partner for the duration of the undertaking.
Spousal sponsorship is open to abuse when individuals enter into non-bona fide relationships in order to obtain status in Canada. The primary intent of the amendments is to create a disincentive for a sponsored spouse or partner to use a relationship of convenience as a means of circumventing Canada’s immigration laws, abandoning their sponsor soon after becoming a PR, then seeking to sponsor a new spouse or partner.
The amendment to section 130 of the IRPR describes new criteria that an individual must meet in order to sponsor a foreign national making an application for permanent residence as a member of the family class or the spouse or common-law partner in Canada class.
Amended Provision
It is important to note that there is no change to the existing regulation 117(9)(b) that states that a sponsor is ineligible to sponsor a spouse or partner, if the sponsor has an existing sponsorship undertaking (in respect of a previous spouse or partner) and the period of that undertaking has not ended.
The amended R130 includes a minor editorial change to subsection (2) and a new subsection (3) which provides for the five-year sponsorship bar. Changes/additions are highlighted in BOLD and the new Regulation reads as follows:
Sponsor
130. (1) Subject to subsections (2) and (3), a sponsor, for the purpose of sponsoring a foreign national who makes an application for a permanent resident visa as a member of the family class or an application to remain in Canada as a member of the spouse or common-law partner in Canada class under subsection 13(1) of the Act, must be a Canadian citizen or permanent resident who
(a) is at least 18 years of age;
(b) resides in Canada; and
(c) has filed a sponsorship application in respect of a member of the family class or the spouse or common-law partner in Canada class in accordance with section 10.
Sponsor not residing in Canada
(2) A sponsor who is a Canadian citizen and does not reside in Canada may sponsor a foreign national who makes an application referred to in subsection (1) and is the sponsor’s spouse, common-law partner, conjugal partner or dependent child who has no dependent children, if the sponsor will reside in Canada when the foreign national becomes a permanent resident.
Five-year requirement
(3) A sponsor who became a permanent resident after being sponsored as a spouse, common-law partner or conjugal partner under subsection 13(1) of the Act may not sponsor a foreign national referred to in subsection (1) as a spouse, common-law partner or conjugal partner, unless the sponsor
(a) has been a permanent resident for a period of at least five years immediately preceding the day on which a sponsorship application referred to in paragraph 130(1)(c) is filed by the sponsor in respect of the foreign national; or
(b) has become a Canadian citizen during the period of five years immediately preceding the day referred to in paragraph (a) and had been a permanent resident from at least the beginning of that period until the day on which the sponsor became a Canadian citizen.
Implications
The amendment, which came into force on March 2, 2012 upon registration, bars a previously-sponsored spouse or partner, from sponsoring a new spouse or partner within five years of becoming a PR even if the sponsor acquired citizenship during that period. Other members of the family class will not be affected by the regulatory changes.