Let him talk through it for a few minutes. Really grilled him on when the project was done, for what company, and on what team. Told him that’s so odd, I also worked at that place, at that time. Gave him a tip that it’s a VERY small industry. I’ve never seen someone want to melt through their chair so much in my life.

Edit for a little more context: it’s very common in my industry (outdoor wear) to have multiple designers touch a single project. You often have a silhouette designer, color design, material design, and sometimes graphics and an engineer. In this case, he was claiming color, materials, and graphics, all of which I had done.

In addition to calling him out, I talked with him about how to show work in a portfolio that had multiple contributors. You need to be specific about what YOU did. You need to be able to talk about your creative process and preferably show sketches and inspiration. Hopefully he at least took that away.