Your lawyers probably don't know the difference between a tool and a library that is used in a published product. The code of a GPL licensed internal tool is no

Your lawyers probably don't know the difference between a tool and a library that is used in a published product. The code of a GPL licensed internal tool is not linked to the product (in the programming sense: there's no "object linking" or mixing of the code). You don't even need to release the source to the public if the tool itself is not available to the public.