So, he lied to regulators, persuaded airlines to remove training on MCAS and bragged about it. (knowing it would activate in extreme circumstances)
After he found that boeing had changed the design and made mcas work more often. He did not raise any alarm bells and just kept quiet...
He deserves the trial... He did have at least an ethical obligation of saying "hei guys, I was wrong, design changed, please re-evaluate" even if it meant getting fired.
Also, the fact that Boeing can change design without guarantees that FAA and customers are informed is a bigger problem...
'ensuring that regulators and airlines perceived the MAX as so minimally changed from the previous 737 model that pilots would find little difference.'
What is consistently not discussed is that moving the engine mounts forward, to fit the larger fans, seemingly should have called for a new type certification. That would be epic expensive, so FAA and Boeing and airlines went along with the software tricks to make it appear to pilots to fly like other 737s. That works OK in most flight conditions, though can be occasionally catastrophic.
The problem is definitely beyond this one person.