Rewatched The Mist and rewrote the ending in my head on a slow Tuesday

So I watched The Mist again last week while I was home sick in Boise with a fever, and I got stuck on that ending where the dad kills everyone right before the army shows up. It always bugged me that he never just waited one more hour. So I started playing with a fix: what if he hears the tanks coming while he's still holding the gun, and he has to decide right then? I think the better version is him chickening out, just flat out refusing to pull the trigger, and the others turn on him for it. Then the military rolls through ten minutes later and he has to live with all of them hating him and his kid being alive but terrified of him. That feels more like real life to me, no clean mercy, just a guy who couldn't do it and now has to deal with that. I even sketched it out on a napkin at the kitchen table. What would you change about that ending, or is the original one already the right call?