... the risk of which is completely negated by dancing in/out/around LOS as necessary. And its the tanks job to make sure the reaping occurs somewhere players can LOS-dance. (near a pillar etc etc).
Most common mistake ive seen in my groups (besides tanks pulling fresh packs as a reaping occurs) is tanks just letting reaping happen when it happens, without any regard to whether there are LOS opportunities at that location. Its not a big deal in lower keys but, at some point, it becomes a key factor.