Definitely don't give up on it, its got buds already and they will get bigger still. I do think your friend went way over board. The idea of spread the plant out like that is great honestly, but should have been done in veg so the center had growth that filled in for more bud sites. Thats what training is all about maximizing the amount of canopy you can get light to
. I also would not have removed all the other leaves. I have nothing against some selective pruning, meaning removing a few leaves here and there to allow better light penetration or air flow. But he "defoliated" your plant. Now you are lighting up the stems, soil, and floor instead of the leaves. I really don't understand what guys that strip plants completely like that are thinking. Its going to slow in growth after being striped like that, and then it will pick back up the budding process. It will probably regrow a bunch of leaves first though. It will be much more impressive in about 6-7 weeks either way. As far as when it will finish, that is a question that can't be answered for another 6-7 weeks. Every plant progresses at its own rate. The genetics and environment will determine how slow that happens. Your plant has experienced some heavy stress, which will most likely slow it down.