well, if he gave them the copyrights, then they belong to the company.
typically, it\'s a matter of was he getting paid to churn out material for the company. they paid him for the original material, so it became their property.
however, there are exceptions to the rules, if he claims copyright, he might win a case dependant on what his claims entail. say he claims he created them years before and was informed that he was simply being paid to give them licence to use the textures in their product. in that case, they would still have the right to use them in the product, but he would have final copyright and capability to use them as he sees fit.
copyright laws something that can be considered art are complicated, and I\'m having a bit of trouble learning them, but this kind of thing was covered last semester.
[edit] I knew copywrite was wrong, but I had to make sure.