Well, that's not about semantics at all. The question was whether it may or may not happen. The answer is "yes, it may happen". Because it happen in the past, and there is nothing in the Immigration Act and in rules of application assessment process which would prevent this from happening. Now speaking about unlikely, can you measure how unlikely it is? You know, chances to die in plane crash is one in 11 million, but it is 100% to those, who already died in plane crash.
You think, you know enough about immigration process, but you actually doesn't. Your knowledge is mostly based on the information you reading in this forum and your own experience. Believe me only something like 1% (my opinion) of people who got rejected posted here about their rejection. I am on this forum much longer than you and I myself struggled with immigration process for 2 years. And the only thing I learned about dealing with CIC, is uncertainty. You would not believe for what reason ppl got rejected. You can't say you're PR until you get your CoPR signed.