Thats pretty much weird. I can tell you from the first hand that I had implied status while working on IEC. Since my LMO got rejected, after a month I received a letter from Service Canada which stated the exact date when my status stopped to be valid. That date was approx 2 months after expiry date of my WP. I also have many friends who were under implied status after IEC.
I can't find the link now, but I've read the definition of implied status in some Operational Bulletin, which officers use when they assess applications. But here you can find more about it: http://www.cic.gc.ca/english/resources/tools/temp/visa/validity/implied.asp
It is clearly written: "If a temporary resident applies for renewal of their work or study permit and their permit expires before a decision is made, R186(u) and R189 (the right to continue working or studying under the same conditions pending a determination of their application for renewal) apply only as long as the person remains in Canada."
Glossary http://www.cic.gc.ca/english/helpcentre/glossary.asp#i says "If a visitor, student or foreign worker applies to extend their status, before that status expires, they can legally remain in Canada until a decision is made on the application. In this situation, the person has implied status."
Now, some people are confused with how to get this status, and they think if they only applied for LMO/LMIA, that's sufficient. Well, that's incorrect. You can benefit from implied status ONLY if you asked for extension/renewal of work permit. With that application you are asking to extend your status, what means you are asking to extend a status of a temporary resident, because that's what visitors, students and TFWs are. Also, with concurrent processing you are not asking (and please distinct this) to extend your work permit. Extending work permit is something else. In case of concurrent processing (which means getting applied for LMO/LMIA and work permit in the same time) the applicant fills the form which is called "Application to Change Conditions, Extend my Stay or Remain in Canada as a Worker", what means that the applicant is asking to change the conditions. You are not actually extending your current IEC WP.
It is also questionable how long your friends worked under "implied status" and if they really had it or not.
I just know that it IS possible to have implied status if you are working under IEC, because I personally had it.