A former artist or even an outsourced artist probably delivered them a texture sheet of graphics, nobody caught that several of the graphics were plaigerized, the artist never mentioned it, assumed it was purely for a blockout or temporary, maybe they used it during a mood boarding/visual development stage and it got pushed along the pipeline.

Trying to reverse search graphics your artists make for you would probably not be done in the good faith sense, if there wasn't suspicion that it wasn't original anyways? But happening four times seems like a reason to really crack down on that kind of thing for the future ... Bungies management has also constantly had issues too.

Artists use photobashing all the time to develop concepts since timelines push design work faster and faster. Photobashing other artists work is usually an issue but taking images or conepts within creative liberties through sufficient alteration or "transformative" use is typically the move if it was ever done.

I'd call it a management issue. Probably bad oversight of outsourcing, or maybe internally disorganized production. Also text and graphics seems like they'd probably have vetted the designs and someone really tried to pass it off without raising attention somehow ... So I'm guessing outsourced and not an internal employee? Idk.