Our bylaws include behaviour by “occupants” which would probably cover this situation if they had the same.
He may be occupying the apartment but if he isn’t on the strata roll, then he has no official standing when it comes to Notices to Comply and potential fines. They would be the apartment owner’s problem, as they are in this case.
The simple answer would be to hammer the apartment owner until they did something, but it wouldn’t do much for community spirit and there’s no guarantee that Tribunal action would fly if the owners could show they were doing everything possible in their limited power.