A question about nfl rules/ fumbles?

watchin the green bay game right now and it looks like after 13 years of waiting ill see them in the superbowl (maybe). anyway the bears punted it and i think it was williams muffed the punt but we recovered. also there was a foul on the field witch was uneligable man down the field for chicago. so my question is if chicago had recovered the fumble on that play would their penalty override the fumble or would the bears just go backwards 5 yards from where they recovered the fumble?????