p15: "Only the Development Team can change its Sprint Backlog during the Sprint"
p10: "If the work turns out to be different than the Development Team expected, they COLLABORATE WITH THE PRODUCT OWNER to negotiate the scope of Sprint Backlog within the Sprint".
So P10 implies that the Development Team CANNOT change the Sprint Backlog (or at least the selected Product Backlog Items within it) without collaborating with the Product Owner. However the question in Mikhail Lapshin's PSM examples takes the p15 interpretation and marks the p10 interpretation as wrong.