OP here...to clarify the ticket is non refundable. One other minor detail I left out of my original post is that the fare was exactly $6,661.

Someone mentioned, what happens if my former employer finds out after I've flown the first leg and cancels the return, and then I would be stranded. I'm not concerned about this as I plan to fly back home within a day or so. If for some reason I was unable to use the return flight, I have the means to get back weather it would be via miles or just purchasing a return flight; however, it would be embarrassing if they found out.

I'm also not concerned with gaining goodwill and looking like the honest guy for coming forward about this, only concerned with the opposite. Would appreciate any insight or ideas anyone has on how I could possibly fly under the radar with this one given the ticket was purchased and paid for so long ago...