Really sorry to hear about your misfortune. It is very frustrating and makes one furious when a bike (or anything, actually) is stolen.
You're probably correct. I had an e-scooter stolen from my "heavily-guarded" residence in the middle of the night. There was no battery in it (upstairs being recharged) so they would have had to push it through not one, but two locked & "guarded" pedestrian gates. I feel the same about an inside job. Our "guards" are tiny young migrants being paid pittance to do a very shitty job. Supplementing their income probably seems quite rational.
We need a Beijing CSI. According to television, the crime could be solved in less than 60 minutes, usually by sexy lab techs.
Give us the Youku link after you've uploaded it. :)
One of the reasons I am an advocate of legal bikes is to purposefully NOT be a customer (supporter) of the stolen bike trade. Hidden on the other side of that "great deal" is someone shedding a lot of tears.

