Ron - there's no "right or wrong way" with these situations. However, I'd submit that, oil for the cylinders is from beneath the piston, and a loss of oil pressure isn't usually associated with a broken ring. If his motor cranks and runs, but then looses power, suspicions would be head/valve train (damage to the cam, rocker, valve, etc). Pull the valve cover first anyway, it will usually tell you how deep you have to go to repair the damage. But the head is probably coming off shortly anyway.
Me, I'd investigate as I go, turning, measuring, observing. It's a good sign that his repeated oil changes didn't contain any measurable metal or alloys! Quite possibly, he did such a good job building it, and quickly enough to stop the motor, that he may not have done any real damage. Or at least, minimized the damage.
And the oil pump and returns fortunately are outside the engine, so fingers crossed, he won't be pulling cylinders or splitting cases!