He had to wear a Patriots shirt or some form of team logo. The Patriots told the Browns they were there and so wanted to look the part: “Yes. We’re the Patriots. See our guy with the shirt? And we’re totally legit too. We’re just hear to film a feature on former Patriots’s (Yeah. That was the ticket we told you about.)”
Problem was is the Patriots didn’t inform the league about this until after they filmed. And they didn’t inform the Bengals who just happen to be their next opponent.
So, they’d better be wearing Patriots swag when they told the Browns what they were doing. Otherwise the Browns security would be wondering how to keep an eye on them.