Some people are bored enough to break the law in order to find distraction. Why not get a wild cat like a serval (even if they're illegal in Nova Scotia)? Maybe because wild animals are themselves bored, when kept in captivity, and reputed to be great at recovering their freedom.
For anyone who's owned a cat and tried to keep it inside, feline escaping skills should be little surprise. What I find slightly surprising is the transformation of courage into fear visible in this encounter between very different cats. It seems the legal cat got its daily dose of adrenaline... Angle matters!