[PeterisP]

Red teaming isn't limited to "get into a company" testing of networks, it's also used for testing products and infrastructure that's outside the company. For example, you can reasonably have a red team evaluation of some authentication or payment infrastructure based on smartcards or mobile apps, and that'd inevitably include reverse engineering of all the artifacts that are available to the users; and in such cases also likely that many/most software parts of "your" product or device aren't made by you but redistributed from some other vendor, and you don't necessarily have the source available for that.