reprimands that are not attacks
I offer the following non-aviation-specific comment in the hope that it is helpful in this situation too, and I hope noone objects:
Awhile back I got sent on a management course which had a segment on how to reprimand someone touchy who has done the wrong thing without (or with reduced chance, anyway...) that you will seem to be attacking them directly.
The overall idea is to make them realise they've done it wrong themselves. The suggested technique is to ask them what is the previously agreed action, or procedure, or ethos, or whatever (your approach briefing, company SOPs, aircraft limits, etc), and to discuss this with them until they've acknowledged the agreement to do one thing (can be pretty short "Do you recall our plan?"). Then state what they actually did, and ask if that meets the agreement (if you are doing this right, it won't and they won't be able to argue without it being obvious rubbish). Then state or discuss how to do the agreed thing in future, and ensure they agree with it.
Then they will see the difference between their view and reality, and feel a commitment to the agreement you manoeuvre them into making.
It sounds like a nightmare situation and I hope you resolve it well.