I am in no doubt the players have witnessed a coach behave in this manner at trainings previously.
The profanity and the slamming of the coaching board (were the papers flying all over the floor CGI?..... joking, but it added another level of drama!) are not troubling to me, and I suspect the players moved on quickly (unless it is a frequent occurrence which will become a source of frustration for the players).
However, Coach, knowing cameras were present, clearly makes a point of blaming the players for making him "look like an idiot". Translation: I am not the problem, it's you, and I am happy for the public to perceive you as such.
For most of the local players, I doubt that going down well and is likely to linger well beyond the moment.
Like others have said, with cameras around, this is a behind closed doors discussion with the worst offender(s), and probably best assisted by recorded visual resources of games/trainings to provide constructive feedback to focus on the issue.
Wells attempt to humiliate the players, and whether cognisant of that or not, is a high-risk play given everything that has happened at the organisation in the past 10 months.
Should real performance pressure come down upon the team early in the season, the players are just as likely to turn on Wells out of insecurity due to moments like this, then play harder for him because to me it appears he has (perhaps inadvertently) a 'me' and 'them' dichotomy mindset.
What he says in front of the cameras when being questioned is all contrived to make him feel better about his actions.