It's interesting on how that happens. Last year while walking the desert at a known older site I spotted what I thought was a folsum under a creosote bush. I got on the radio and proclaimed my find. I was about 20" away when I spotted it. Kept my eye on it taking photo's while walking to recover it. My buddies wife came over as I was taking close up photo's and then recovering what turned out to be a confirmed (by two authenticators) a clovis point.
I walked back to where I was standing when I first noticed the point to show my friend where I was and she looked down next to my feet and recovered a perfect small black point. I stood next to that point twice and didn't see it.
Thats one way it can happen,LOL