Kind of sounds iike the builder did not correctly put "cam lobe lube" on the cam at the time of installation. Or they did, but being a liquid rather than a moly paste, it might have dripped off over night, or similar. But you DID hear and see it run after they got done? In ANY event, contact the builder for their thoughts on things.
Key things: -- the lifters come from the same company as the camshaft, so the cam company's warranty works as it should. Lifters from another company, no dice.
-- All camshafts have some level of "Parkerizing" (metal hardness treatment) to help them last a long time, but as long as most motor oils had enough zddp in them, no problem, usually, as long as the cam break-in procedures were followed. Seems like Comp Cams used to have an option for an extra level of Parkerizing a few years ago. ALL Cam companies now usually sell their own oil treatments for added zddp.
-- Once the engine initially fires, it has to run for a full 30 minutes at 2000rpm for the cam lobes to get engine oil right off the bat, slung from the crankshafrt as there is no other "direct" oiling of the cam lobes via pressure lube (as the cam bearings). This is specific to flat tappet cams, but can also be good for roller-lifter cams, too. UNTIL that happens, the initial cam lobe assy lube is what lubes the lobes and lifter bottoms.
-- What springs were on the cam? Stock single springs or "dual springs"? Cam break-in should usually be done only with the outer sprinigs rather than the outer springs and inner dampers. Once the cam is broken in, THEN the inner springs can be added. This lets the initial break-in period happen with less total spring pressure.
There's a thread in here which illustrates what happens when the divider-bar rollet lifters have a divider bar related failure. On a RECENTLY built motor.
A flat tappet cam, when correctly broken-in, can last a very long time. Not many really "street" roller cams, by observation.
Used to be that for Mopar Perf items, the local Chrysler dealership's service department would be the ones to approve or disapprove any related warranty claims. Not sure how that might work now, so read that information online or in the literature which might have come with the particular camshaft.
Just some thoughts,