But this bounding box can be more or less precise, and that’s why we have our second parameter. In short, if this parameter is set to true (false by default), then the bounding box is closer to the mesh (OBB bounding type), but it’s a more costly calculation. Be aware that this type of bounding box is especially useful when your mesh is rotated to an angle.
The docs mention that the bounding box used in precise is closer to the mesh, not the mesh 