There is an open question about whether some persons with protected person status are subject to the cessation provisions in IRPA Section 108, but a "Convention refugee" is almost certainly among those covered.
I am no expert in refugee law, which has many tangents, nuances, and complicated technicalities. Among matters I cannot come close to explaining is who or why or when some "refugees" or "protected persons" have their home country passport returned to them. From what I have seen, anyone with refugee or protected person status, including those who are granted PR status, should presume and proceed on the assumption they are covered by IRPA Section 108, the cessation provision in Canadian law (see here: https://laws-lois.justice.gc.ca/eng/acts/I-2.5/page-13.html#h-275708 ) . . . UNLESS they have been clearly advised by a totally reliable source otherwise, such as a reputable immigration lawyer specializing in refugee law.
The consequences are so severe it is not a good idea, not at all, to be playing the odds.
While I do not know who gets their passport back, who does not, or how that relates to their status as a refugee or protected person, I have, nonetheless, seen enough cessation cases to recognize that the fact the passport has been returned to the individual does NOT mean they are not subject to the cessation provisions under either the UNHRC cessation provisions or Canada law as prescribed in IRPA Section 108, which are the same, the Canadian law specifically based on the UNHRC provisions.
Which is to say just because IRCC returned the passport does not necessarily mean he is not subject to cessation provisions.
An aspect of this I do know is that the nature of the underlying threat, whether it is from the state itself, or is from a non-state threat, does NOT determine whether the cessation provision applies. When a person qualifies for Convention refugee status based on a non-state threat, the situation must still be one where the state fails to protect the person from that threat. That is, the individual is granted protection because the country where the individual was living, typically the country of nationality (slightly different scenario for stateless persons), fails to provide them adequate protection.
So, the fact that his grant of refugee status "was not against the state" does NOT mean he is not subject to the cessation provisions.
Note, it is IRPA subsection 108(1)(a) that most refugee PRs in Canada run afoul of if and when they obtain or use a home country passport. This is the provision terminating protected person status if the individual has "voluntarily reavailed themself of the protection of their country of nationality." For example, applying for and obtaining a new or renewed passport is an overt act which is deemed (presumed) to constitute reavailment. Travel to and entering another country using the home country passport is an in-fact act evidencing reliance on the home country's protection (it is entering the country under the protection afforded by the country issuing the passport).
All That Said . . .
Your friend is probably correct that there is very little risk of reavailment proceedings if he uses the passport that has been returned to him to travel to the U.S., and perhaps to any country OTHER than the home country.
He is NOT entirely correct that "there are no cessation cases where they cease applicant who traveled to other countries using a home country passport." They have, and in such proceedings the official decisions upholding cessation have quoted such travel as actions supporting the cessation decision. However, there are almost always additional reavailment actions, typically including travel to the home country.
What he probably means is that they do not proceed with cessation against a refugee ONLY because the PR-refugee used the home country passport to travel to countries other than the home country. I am not sure he is entirely correct about this, but at the worst that is NOT common, and the risk is probably very low.
To be clear, however, that is ONLY about using the passport returned to the refugee. DIFFERENT situation if the refugee were to apply to the home country to renew the passport or to issue a new passport. Applying for or otherwise obtaining a new or renewed passport is not only something that is evidence of reavailment, it is PRESUMED to be reavailment.
EVEN THEN . . . however . . . it appears the risk of cessation remains low so long as the refugee does NOT travel to the home country. The vast majority of cessation cases in Canada against PRs appear to involve travel to the home country. So, absent travel to the home country, it appears (emphasis on APPEARS) that the risk of cessation is low or even very low.
BUT there are TWO CAUTIONS about this:
-- as noted, again and again, the consequences are so severe that any risk should give a refugee pause before taking the risk (the risk of falling when walking on a ledge are the same whether it is three metres or thirty metres above the ground, but the likely consequences of a fall are very different, making it far more dangerous to take that risk on the higher ledge)
-- Canada has been governed by a largely immigrant and refugee friendly government, the Liberals, for many years now; in contrast, the law applying cessation to PR-refugees was adopted by the previous Harper-era Conservative government, and between 2012 and 2015 that government appears to have been far more aggressive in pursuing cessation cases; obvious risk is that this very narrowly held Liberal minority government could be out of office and a far less friendly to refugees Conservative government in place anytime . . . so the pattern of enforcement could change dramatically following an election, a more aggressive approach to cessation pursued . . . what gets a pass today may not get a pass in the coming year
