You're right you can have both. However I feel pretty strongly that filming dismissals will have a negative impact on company culture. Filming the meeting is humiliating. Current employees are aware of the practice and by not questioning it I think they'd feel complicit in the humiliation of departing co-workers. I think this would degrade the overall atmosphere. Indeed having witnesses is a good idea. And I'm all for employers and employees protecting themselves. However the protection doesn't need to be cruel.