Valve adjustment almost a catastrophy...

Eeeek, close call! Had similar thing happen back in the mid 80's. Was working on a guy's rare 67 vette with original 435 horse triple carb. Shot something out of the vise, tink, tank, thump across the garage, forgot what it was. Valve covers were off and distributor was out. Looked for an hour or more. It went down the dist. hole and was laying at the bottom of the oil pan.