The Rosevelt Captain’s command was terminated as he violated the chain of command. There was a proper route to report the issues via classified channels. He chose an open channel that ended up emblazoned across the San Francisco Chronicle.
The Evacuations could have happened without making headlines. But by posting it the way he did he brought shade onto the Navy the DOD and his own command. He also flagged to potential adversaries a weak point in the USN.
Now I am not saying that being a Whistleblower isn’t needed from time to time but he should have first gone through the Process if easing the alarm via the Chain of command. If that failed then the open channel. This is grounds for a Courts Martial the first step being to terminate his command.
Acting Secnav was correct to terminate his command. President Trump however responded to political pressures which nearly countermanded the order by SECNAV. This in turn was in essence a rebuke of SECNAV. SECNAV then reacted in turn as required by such he resigned.