You really think there are "US moles in Sinopec"?
It seems like China trying to hedge its bets here. While China publicly denounces the prospect of sanctions it still votes in support of sanctioning Iran when it comes to UN resolutions. I guess its trying to have its cake and eat it too, nothing wrong with that, we all like cake. Id also say that China isnt stupid and will not risk any energy supply shortages while being caught up in politics.
If I had to read between the lines I would say the US has been backroom talking with China and advised them of their intentions. More sanctions are going to be imposed whether China likes it or not and they will need to adjust accordingly. I think the credit issue is just hot air, China is again just trying to hedge its bets here by saying to Iran. "Hey Iran we are on the fence here, we are stopping the oil imports because of the credit reasons, nothing to do with the impending sanctions, nothing suss, ok mate?"
Ok maybe China wont say "mate" but u get the picture