On keeping it objective, brush up on nonviolent communication statements.

Basically only speak about things that have can (as in video camera could capture them) been observed (and ideally have been documented).

“Your start time is 9:00am. On 17 occasions you arrived after 9:45” is clear and clean.

“You’re always late” - hardly provable and there’s always an exception.

“You are not reliable” - very vague and based on the speaker’s subjective criterion for reliability. (A camera cannot record the “not reliable” subjective evaluation and so it would bring up defenses.)

I teach NVC — hit me up for a 15 min zoom intro.