That is very uncommon I don't think I have ever seen that unless the fence is less than 4 ft or there is a tree right next to the fence where they can climb partway up the tree and over , I have seen at least at the pace I lived in that they dig small hole under the fence and get in that way and these hole can look tiny, but they still squeeze through them, I literally put large rocks under my whole backyard fence line ( this was the 1990s) because my Shepard would sneak out while a coyote snuck into eat his food last time was a large moose bone.
I thought that my Shepard looked smaller until I got closer, and it was a Coyote chewing on the bone spotted me ran to the hole took off, 3 seconds later my Shepard came in I think he was getting it on with the coyote females lol which is bad because the half coyote mix dogs are extremely smart and a huge problem in farm areas