The situation is really weird... My friend's relatives have US green card. He's polish but also a Canadian citizen (his wife is polish with Canadian GC). However the guy got a job offer in Asia. So... He drove back to Canada and flight from Montreal to Asia. He plans to return in 3-4 years and file for citizenship like he was living always here (he has DL with the address where my friend lives). He states that because they don't check Canadians on border noone will know he left US. Is that indeed true? 
P.S. Please, don't start venting on how bad he is and that he violates. Yes, he DOES. And I personally consider it as BS and very much against what those people are doing.
P.S. Please, don't start venting on how bad he is and that he violates. Yes, he DOES. And I personally consider it as BS and very much against what those people are doing.