Exactly my thoughts. He said tightened them with a breaker bar. That's what they're good for. Breakin stuff. You can over tighten a fastener and when you do, they stretch. When they stretch, they actually loosen up.
Now, I have done this trick to all of mine in the past. Clean the bolts, cams and frame brackets up good. I mean operating room good. Then, with a center punch, punch a series of divets in the bracket side of the cams and on the brackets where the cams tighten down. This will help lock everything down tight when you tighten them down.
All that said, I agree with others in that something is moving somewhere. You could mark the cam bolts so that you can tell when you come back from driving if it's them that's moving.
