must have been given at least 30 days notice
Not necessarily.
I'm not suggesting that I know anything about the situation at Sterling, but notice given depends on the employment contract signed.
If an employee hands in their notice under a contract requiring a month's notice but says he or she want to leave at the end of the week, there isn't really a lot an employer can do about it. Obviously, that employee would only get paid up to the point of actually leaving but it would be futile for an employer to sue for breach of contract.
Not suggesting for one minute that that's what Sterling's CAM did but there are scenarios where less than 30 days notice could be given. Most likely, Longmint dragging their recruitment heels again.
Let's just hope that someone who knows how to run an aviation business comes along in time ....
Cheers
Whirls