Workers comp question

I have already had CTS surgery and it was done under my employers insurance program that I payed on a weekly basis. I am now going for workers comp and seen somewhere else where they will not allow my claim since my insurance already paid part of my medical bills. I still have a trigger finger that needs operated on, workers comp has allowed both claims, but my employers MCO and my employer have denied the claim, so I am waiting for a state hearing , Meanwhile my employers MCO have offered me a settlement of $1500. So my question is can I be denied workers comp for already having insurance involved. I tried to get workers comp involved earlier before my surgery,but the human resource person in so many words said it wasnt work related, and after my the Dr. I'm seeing now said that it is work related I was a little more forceful in getting workers comp involved. Any help would be greatly appreciated.

Thank you,
Bruce