No compression-next move?

I had the same thing happen with my son's Scamp. He took it up to the local station to fill. Calls me up, won't start. Pulled it home. Replaced cam and crank sensors. No start. For some crazy reason, I pull the cam sensor and take a peek inside. Looked like the tone ring was going back and forth(front to back). Pull the front cover. Spun the cam bolt out by hand. The gear was loose enough, that with the movement, the sensor didn't pick up. I now loc-tite all hemi cam bolts.