I think they have cracked some parts of https. If you make a prior to a non blocked page in https and then go to a block page sometimes it works. If you make your first https connection to a block page it is blocked. Maybe this is due to the way https works. I haven't looked into it.

Google uses https and they still managed to monitor all the traffic and block keywords.

There is a good reason why it is stated change your passwords before you come to China and after you leave.