If the saved path was a network location that does not exist at Company B, Autodesk Civil 3D looks in Company B’s default catalog location. If the part is a standard Autodesk Civil 3D part with the name unchanged, it uses the one in Company B’s catalog, regardless of whether it resembles the one Company A intended.
If the part is new or a renamed standard Autodesk Civil 3D part, the software looks in Company B’s catalog for the most similar part.
Solution: Company A provides a copy of its parts catalog along with the drawing, asking Company B to reference this catalog, or update its current catalog to include the changes. Ideally the changes are clearly identified so that Company B can determine whether the updates from Company A would introduce any unwanted changes to other drawings.