Not only do I think it is good for the Cowboys to send videos to the NFL and complain about calls or ask for explanations, I think they need to do what Belichick does. Talk to the refs before the games and plant seeds in their heads. I have no doubt the Raiders, whose acting HC used to coach for the Cowboys, were aware of Brown's poor technique of not playing the ball and tried to take advantage of that. Pat Kirwan said on his radio show he thought teams were talking to the refs about Connor Williams and his holding. That's why he was getting so many holding calls. He said when he was a team official, did not mention the team, he used to talk to the refs before games about certain players and he claimed it works. The refs will pay closer attention to that player.
There is nothing wrong with letting the league know you are unhappy with the calls going against you. And there is nothing wrong with trying to get every advantage you can for your team.