Plywood is made from wood particles glued together also. OSB is plenty sturdy if its protected correctly - if its not, it'll fall apart.
Are you sure the woman's coop wasn't particle board, or handyboard, or something along those lines? If raccoons are chewing through standard 3/4" OSB that's properly painted and the edges sealed, nothing is keeping them out. (OSB is actually structurally stronger than plywood)