Huawei decided to import HP components from the USA and re-export them to Iran to get around US sanctions. Huawei also has a presence in the USA, but in general the USA subjects any company re-exporting American stuff to sanctioned countries as breaking American law, and actually so does China.
Now...let's say some American executive happened to be in China and China accused this company of re-exporting something made in China to another country that China was sanctioning. Yes, they would go to jail, there wouldn't even be an outcry over it. There are other things the Chinese could get them on, so not even this pretext is needed, but you better believe they would do it.
Now, let's say some Swedish citizen is accused of violating Chinese law but is not in China, rather they happen to be in Thailand. Yes, the Chinese are still going after that person as well, but no, the Thai government isn't involved. They just go and kidnap the guy.
Ok, so now we get to Canada, who has an extradition agreement with the USA. The USA puts in a request for her extradition because they accuse her of violating American law. There is a valid accusation, though it is questionable if she would have been convicted. Canada says: ok, we have to evaluate if this order is correct, so they arrest Huawei daughter, and then it goes to the courts. China tit for tat grabs some random Canadians off the street, throws them in jail for a couple of years (Huawei daughter is in jail for a couple of weeks then at home under house arrest for the rest of the time, but that's canada for you). Eventually, Canadian courts decide on their own that America's request isn't valid and they decide not to extradite Huawei daughter to the USA (the Canadians arrested in China wouldn't have mattered, because the courts are independent and they can't make "deals" with other countries).
China is really just rule by law: they don't like you, you are going to jail. The USA, and Canada, have laws, independent courts that aren't subject to whims of prime minsters or presidents, etc...they even have bail where you can spend 2 years in your Vancouver mansion rather than a Chinese prison while your case works its way through the system.
They are not comparable.