Fincher's proposed ending would have been interesting. Ironic, too, it would have more in keeping with the overall tone of the film. As I understand it, in addition to not showing the head, & Pitt shooting Doe, Pitt also insisted on Somerset's ending quote & the shot on him in the squadcar, etc?

I'm usually a fan of not overdoing endings, e.g. Casablanca or Double Indemnity, Blade Runner. Keep in simple. I actually hate The Mist's ending. I think King's original was much better. But this is hard to imagine, given that it was never actually seen.

Suppose a compromise with the black screen & Somerset's quote?

One final question: did Pitt's contract also require him to agree with Somerset about getting a warrant first, then kick in the door anyway?