I think you are referring to a kulbit by the 360 degree flip. It involves the cobra maneuver but is very different. The J-20 was just executing a loop and I don't think the loop was tight enough to be considered a kulbit.
Comment on Russian engineers working in China:
Many of them could probably be considered Chinese now since they've applied for Chinese citizenship and even had children in China.
can you tell me more abt them? Sounds interesting....
i was just reading tphuang's latest blog entry, even if the relationship changed over the decades, china do owe russia alot for their input. Mind you, they got alot of cash in return though....