If the wind was good I would challenge him. I think if you're that close then you should act like you're coming to take his cows.
This is probably the wrong thing to do and I would hike back to camp sucking my thumb and wondering why I am horrible at elk hunting.
In my experience the bulls go where the cows are during the rut. I look for cows during the summer and the bulls will be there come September. At least in the areas I've hunted.
I agree that solids are just fine and movement and scent are the bigger issues to address but... I think in many situations camo can/will help. If you're a lousy hunter like I am, you need every little advantage you can get. I like to do everything I can to tip the scales in my favor.
That...
I haven't read Scott Haugen's book but I have read Boyd Iverson's book (Trophy Blacktail Tactics 2) several times. There is some awesome info in there. I only have enough time and patience to do about half of what he does and it has paid off tremendously.
Going on a late backpack hunt. Need a good sleeping bag good for 5-10 degrees. My goal is to keep it under 3 lbs and under $200. Brand doesn't matter as long as it's decent quality/condition. Let me know what you have.