an emergency question

Our I140 was approved for both EB1 and NIW and our I485 is
pending though the priority date already passed ours.

We filed Canadian Permanent Residence application (Jan, 2005) before we
ted applications for US green card, since my job at that time was only temporary and we were not sure if we could find a permanent
position in the US. Our Canadian Permanent Residence was approved and then we were asked to make the landing. Our I485 was pending and we were not sure how long it was going to take. Plus, we have spent some money on Canadian PR so we didn’t want to give it away easily. So we waited at the end of the half-year deadline to make the landing, just in case our US green card was denied or was not going anywhere. The plan was to come back to the US right after the landing and continue working and living in the US.

On last Saturday, we came back from Fort Erie, ON the same day we
entered Canada after visiting a friend and making the landing. The immigration officer saw our immigration visa for Canada and also our Advance Parole documents back to the US. He told us it was “illegal” to apply two types of PR status at the same time. So he was going to write letters to Canadian immigration office and also USCIS to tell them this. I told him if we could choose we would like to abandon Canadian PR since we applied that one “just in case”. He said I could make the arguments when I interview with an immigration officer. Of course we were stunned and we had no idea this was going to affect our US green card application, since we heard a lot of people did the same thing.

So my questions is:

1) Is anybody familiar with this situation?
2) What should we do next? Should we wait for the messages from Canadian immigration office and USCIS, or we should write a letter to Canadian immigration office to abandon our PR application here, if that is going to help us on the US green card?

We really appreciate any input here.