Guineas are blind in the dark, even dim light at dusk or dawn really impairs their vision... if they get spooked in the dark and flutter from their roosting spot to the ground, their only instinct is to be still and quiet... which makes it really easy for a predator to pounce. So no, they may not necessarily scream the alarm call, especially if they can't see what's going on. My birds typically only scream the alarm call during daylight hours, when they can see predators approaching.
Seems to me that the only time a predator would leave behind a carcass is if they aren't big enough to get it/drag it off, like weasels, possums, skunks etc (all my lost birds have been dragged/carried off, by something a little bigger). On the ground under the trees or out in the open predators like foxes and bobcats grab, nab and run, so do coyotes... and if they've got the Guinea by the neck, the bird can't really make much noise. If the neck is immediately broken there won't be any sound of a struggle or any trace of a feather trail.
A few yrs before I had my land completely perimeter fenced I had a very brazen (and hungry) predator nab one of my Hens one evening from her nesting area about 15' away from me as I was closing my pasture gates (at dusk), my back was turned and all I heard was a weird 1 syllable squawk sound, so I walked over there to find just a puff of fresh feathers, no feather trail or anything. It was too brushy of an area to be an owl, so it had to be a ground predator. The next day I found her leg with her leg band still on it and some of her spine, down the hill under some poison oak bushes. The ground predators here will leave feathers at the kill site, but usually run off with the bird to feast, and I usually eventually find the carcass a few hundred yards away, under some thick brush. Great Horned Owls fly well out of my 10 acres with their kills, and I never see any traces of those birds again.
One other thing that can cause confusion when trying to figure out what took your bird is that unless you are near when it happens, there's really no telling that what killed a bird is what packed it off tho, could have been 2 entirely different predators... one killing and eating some of the bird, then another predator packing it off and feasting on what is left. Check around, you may find a carcass, or parts of one, more feathers etc. Without seeing the bird in the predator's grip tho, it's hard to know exactly what takes a bird.