I don't think he saw you. I think he was more interested in his scrapes. I was reading an article about calling in big deer. It states that you have to use the deeper grunts and larger rattling antlers to get their attention. The article said that mature bucks won't respond to puny calls or rattles during the rut. So, give it a try. Make it sound like two brutes are going at it. You might get that big boy's attention.

Good luck!