Is it bad to take warfin and lovenox blood thinners my husband was prescribed both and ped away?

he had abdominal surgery and a blood clot and was in the hospital for 1 week and 1 day , was prescribed warfin and lovenox and was still taking plavix and crestor . after being home for 3 days we called 911 because he started bleeding internalily and ped away the following day at the hospital . the death certific says cause of death is dissmented intravasgular coagulation. would this be to much blood thinners and would this contribute to his death