It's not a matter of skepticism, it's a matter of facts. I have 2 friends who did the same thing and were caught working illegally. They had status when they filed their PR applications with OWP and the excuse that CIC call centre told us so, didn't go well with CBSA. They had to go home and had their applications cancelled. It's good that you have it in writing, didn't even know they could do that and didn't think of doing that but still not sure how CBSA would take it nor of course if it's the same thing with IEC and PGWP.
I also have good relations with a couple of high ranked SINP officers who were eager to look into it for me and they told me I couldn't keep working, so I've stopped, although the real life examples of my 2 friends were more than enough to convince me anyway. Also it's not the first time government agencies here have trouble working with one another, I have many more examples.
At the end of the day, it's CBSA who send you home, not CIC and their response was that "we don't care what CIC told you in the phone, you didn't have the right to keep working."