Just to make sure we are using the correct terminology --From my understanding, US citizens are allowed to stay in Canada visa-free for 6 months. After that though, they start getting a bit iffy about letting you back in. He has been in Canada now since April 3rd, so about 7 months now. He has a stamp in his passport showing that he arrived on the 3rd of April. Of course, stuff online isn't always 100% clear, but I feel like it's too much to risk to just hope that he will be allowed back in.
If anyone knows of someone I can contact to confirm, 100%, that it will be ok to fly back, please let me know. Or maybe somewhere I can start looking. Thanks in advance!
Visitor visa or ETA: The document someone needs to ENTER Canada. The person must enter Canada before this expires. US citizens do not require visitor visas nor ETAs.
Visitor status: the status given after being cleared by a CBSA officer an allowed into the country for the purposes of visiting, not working. Usually this is six months but can be changed with a stamp or visitor record by the officer at the border.
OWP: Is work permit. Once someone has a work permit, the visitor status is void. However, visitor visas are stil required to enter Canada if coming from a visitor visa required country.
A visitor visa is not visitor status.
The only people with guaranteed entry to Canada are PR and citizens. Otherwise, there will be an assessment by the CBSA officer at the point of entry. In terms of risk of denial of entry, the risk is lower with a work or study permit and much higher when only on visitor status.
So based on your specific situation, it sounds like he was initially here on six-month visitor status. But before his visitor status was up, his status changed to a work permit holder. Therefore, his visitor status is null and his work permit is his new legal status. He has authorization to stay in Canada until the work permit expires. If the work permit is expiring and he still is not PR, he either has to apply to extend the permit (putting him on maintained status) or change his status back to visitor at which point he will either be issued a new date of expiry of visitor status.