I would argue that borrowing model geometry to re-use in a different model is likely fair use, while creating a similar looking model by hand is likely not.
If they did indeep copy-paste the geometry, that is a clear cut prima facie case of infringement, and fair use is the only defense.
Under U.S. law, I suspect this is a dice roll. Under historical understandings of what copyright fair use is, this would fall squarely under fair use, but there are a lot of pro-business judges that have abandoned originalism and the principles of copyright purpose in the copyright analysis process, often ignoring the analysis of copyrightable aspects entirely.
Under the historical framework, only the aesthetic aspects of a work are copyrightable. Simple shapes are not copyrightable. There is an argument to be made that the geometry copied here is a functional implementation of that simple shape, which is not itself copyrightable. Therefore, the geometry, in isolation and not combined with others, is likely not copyrightable under the historical analysis framework.
Some judges, particularly in the dc circuit, however, don't use this framework consistently, despite the supreme court repeatedly reaffirming its applicability to copyright analysis.