just checking, now they need to lived for 3yr with the 4 years (not 5 yrs) before applying for citizenship.
depends on how old your friend's husband, if only 20/30 + then might be good to try out in HK providing he was born in HK, and only come here at high school or university age. as he do not have any connection here, then does not matter where to start with for the job.
but if he received education (from junior grade upto university) then he could have lots of schoolmates, course mate that might refer him with good decent job. then why bother to go back to HK.
have to live in canada for 3 years within the 5years period.
but if your friend already thought she will be in "JAIL" then why bother to come. As her husband is already canadian citizen, she could come to live here anytime she wish to settle down....