It's impossible to know from a pic... As far as a burn, it's possible the burn happened in the previous, more sunny spot and took a while to manifest on the leaves. The way they lean, they end up having a top/bottom, one side that gets light, the other side in shadows. If cut & one happens to put the piece the other way so that the side that was previously in shadow is now in a lot more light, burning could occur in the same amount of light that one thought the plant was already used to. I've burned pieces of that before, which looked like your pics, but doesn't look like I uploaded any pics to the DB entry.
If the roots are rotting, I don't think it would look like that. If you're concerned "overwatering" could occur, you could put more bark &/or perlite in the mix. This species should be growing at a noticeable speed in your location at this time of year.