Sounds quite likely, Lyjema, although it could have been a joint effort with fox pulling the roof off and hog pulling out some of the straw – difficult to say. But hogs are sometimes quite fussy about what they have in their houses. Equally fox could have been trying to get hold of what was in the box.
It may be considered unusual, but foxes will on occasion kill hedgehogs and some individuals apparently become quite expert at it. It is always safest to be wary and, if foxes are around, if possible feed/house, the hogs somewhere foxes can’t easily get at them.