This is an odd one, but the answer may be complicated.
In the upper peninsula of Michigan there are places that enforce strict environmental rules to protect the community and closed habitat. These places have rules like "no cars" or "mass transit only". These locations have gotten creative with how they compensate employees for their travel time. This is unusual because unlike most cities, transportation is not on the employee, and they can't usually "move closer". You go when the ferry, horse team, or electric bus goes, and that may only be 2 times a day.
There are also other parts (Mackinac Island for one) that ban cars outright.
The real trick are that these are usually smaller towns and don't really have a big business culture. But it does mean having to adjust to the area a bit.
For example, I could see. "We offer 20k a year for a 40 hour work week, but we understand you're coming by ferry so we don't expect you here till 10am and you can leave at 4pm to catch the evening ferry" turning into "But you live here now, 9am to 5pm, you don't need to catch the ferry."
In which case I think the request is totally reasonable. They were effectively paying you to sit on the ferry because it was "the cost of doing business" in that area. Now they're not willing to pay for you to "sit on your couch at home" just because you moved closer.
If on the other hand you were to work 40 hours and now they want you to work 50 hours, that's a bit much.
To me this sounds like your friend "shortened" the story quite a bit, and is leaving out some important parts. They may have to "work" more hours because the company is no longer going to pay for the ferry trip the employee no longer needs to take, but that doesn't mean it's "overtime".
What it really comes down to is; was the company compensating its employees for a long, or time consuming commute, and now refusing to compensate this employee because they are not making that commute (totally fair and IANAL — legal) or are they trying to force him to work a 10 hour day because he is closer (not fair, not IANAL legal)?
Some things the employee could try are
taking a three hour lunch. If they are trying to get people that live closer to cover time that that people further away are not able to do, then maybe he can suggest a really long lunch to even out the time and give the company what it needs. Of course that will depend on if that has value to the employee.
convert to 4/10 hour days. This is fairly common, and may be worth it. Again, it gives the company the time coverage, but the employee gets what they need too. Time off.
Come in early/leave early or come in late/leave late. Again, if the company is just trying to get coverage, they may be willing to have the employee start OR stop in different times to keep an 8 hour day, but still get that coverage.
In short, it's not odd that a company would need to make some kind of adjustment for its environment, specially in the UP. These adjustments usually allow for workers to get compensated for the travel they need to do to get there, because it's not trivial. In these companies it's common to have "close" workers and "far" workers. Close workers not eligible for the compensation for the far workers, and close workers expected to work different times than the far workers to accommodate for environmental restrictions. It is however odd to ask a close worker to work for more hours then a far worker. But due note that a far worker may be considered as "working" when sitting on a ferry waiting to get to work. Close workers may also be required to "fill in" more frequently the far workers, because frankly a far worker may not be able to get there. Usually this is accompanied by some kind of flex time though.
In any case, on salary, if you're supposed to get 40 hours, then normal operations should result in 40 hours, though some special circumstances may come up that mean you're working 50 this week. But that should be a rare thing and not a normal thing.