My husband didn't submit Proof of employment either. What we sent was:
1. Pay stubs for the year 2012 and 2013 (excluding the month of November and December 2013 cause he didn't have those when we sent the application in)
2. A printout C from the year 2006 (which was the last year he filed taxes in Canada - he's been working in Germany for the past 6 years)
3. Letter explaining the absence of those documents.
None of these was what CIC asked, but he got approved.
One thing I read here on the forum a while ago, is when the sponsor is living outside Canada, they don't really care about Proof of employment or the Printout C. So maybe that's why we got lucky.