Tech difficulties are always painful to watch. We've all felt the frustration of "I tested this thing five minutes ago so why won't it work now when I actually need it?" and I can't imagine that combined with a live audience of thousands. The chat explodes into a mix of people trying to help, and others saying to just ignore it, and then others trying to do crowd control but just adding to the wall of noise.
The tech problem itself is often not even that big of a deal, but when the chuuba really wants it to work and starts getting upset, and then the stream gets out of control too, that hurts.