when I was showing people I always started with "the main problem is that men get their balls in the way". what did I mean? Most people having a problem would approach it as if they were driving a nail. SLAM! tube splits and bends. (and yes, the wives always nodded to my comment).
I would take it, and go tap tap tap - ensuring the tool was perpendicular to the snap (another usual problem), and it would be perfectly rounded over. same crappy snaps. same crappy setter. So yes, I would be inclined to say operator error. Stay Calm - and tap tap tap.
PS. Same comment for Tubular rivets. It's not a nail.