...cam ,bearings and rocker arms all come as matched set($$$$$$$$). I Guarentee that the head bolts will strip in the block...you need to sue the Mechanic who fouled up first. The engine will run loud and tappety with ruined cam bearings so there nothing left to do but spealk to the lawyers.
PS the plastic oil pipe fittings are only about $5 per set so it's seriously false economy to reuse old hardened parts as you have just found out.