Pay attention to the task that Zhai and Liu had to do during their space walk. What had they done outside the craft?
Here is a piece of clue cited from "The Space Report", a nonchinese scientific websitewww.ddhw.com
"Whilst outside the craft, attached via an umbilical cable, Zhai retrieved a test sample of solid lubricant attached to the outside of the module before they were launched. He passed the sample to Liu. Once the handover was complete, 16 minutes into the EVA, both men re-entered the capsule."
It is very possible that (1) some of the solid lubricant fell off from the collecting process; (2) some remaining lubricant on the module fell off; (3) Liu, (who was so excited and waved the flag wildly) might drop some of the collected sample.www.ddhw.com
Finally, I feel so bitter but with deep sympathy for my poor country fellows who have been tricked by so many lies and faked stories recently.