...where the bell dropped down from when Yang Guo held Sun Bu'Er captive, where did the debris go when they smashed the bell through? If someone dropped a bell directly on top of me from the roof of my house, I'd be dead not because the bell missed, but because the ceiling parts that it fell through would land on me and crush me.
Also, how could a martial arts master like Yang Guo not detect FOUR people carrying a couple thousand pounds fly onto the roof and walk around to the precise position when people can detect footsteps on grass? Was just re-reading this part and I realized how silly the plan was.