This is why the Jets are a disaster of an organization. A proper owner would call up the GM and say "hey, I think it's time to fire this guy, what are your thoughts?". If after the convo as an owner you still think you know better than your GM, then at least communicate with the GM that you're making the decision and that the GM needs to fire him. If you want to do it yourself, tell that to the GM.
Maybe all that happened and the reporting isn't accurate or I misunderstood, but it seems like an emotional decision made by an owner with poor organizational and leadership skills.