It's tough because flower stalks take energy to sustain itself and there are no leaves to really photosynthesize. As far as planting, I think she's saying it should've been planted deeper, where the soil level was before (and that first root), up to the green. Appears to be just under the flower stalk . Keep it wet, I'd personally bag it and hope for the best. You *could* cut the stalk and hope there is enough energy stored to put out more growth and plant the stem in the hopes it sparks, or you could let it do its thing and harvest the seeds to plant. It could survive with the stalk and no leaves. I honestly don't know. If it hasn't died yet then there's hope.
It looks like you cut one of the roots off? It looks like the first root is gone or maybe it is just under the soil, idk. Anyway the plant should probably be bagged or domed (or misted) to maintain a high humidity under lights or by a window to encourage new growth. If you bag it, let it breathe once a day or so and if you see new growth, id begin acclimating it slowly by poking holes in the bag. That's what I'd do. If you replant it, leave it alone and don't do anything else to it.