Poopballs

So the other night I'm doing my thing in my litterbox, and I casually step out and walk back over to the loveseat, where the three of us had been sitting until I got the urge to poop.  As always, I stop in the middle of the floor to wash up, and dad suddenly got up and stepped over me on his way toward the room where my box is.  Mom watched him bend down for a closer look and there, about five feet away from my box sat a lone ball of poop!  If I were capable I might be embarrassed, but I don't think we cats can feel such emotions.  Apparently, I've done this before.  I guess that, because I'm such an obsessive groomer I get lots of hair in my system, and, once in a while after I'm done doing my business I don't realize that something's stuck, and it'll drop on my way out of the litterbox.  I guess.  Sound plausible to you?  I get the feeling they think I do it on purpose.  Is there something wrong with me?  Have I shared too much?