Your sure he timed it up wrong? Had something similar on my old 106Gti, turned out the crankshaft woodruff key was fubar and had sheared prior to me taking the cams out to re-build the lifters. I put the cams back in without paying heed to what I thought was a visual illusion but turned out to be the crank pulley turning independant to the crank whilst I was turning it over to get the timing right and hey presto, once back together it bent 8 valves

. Worth checking anyway whilst your doing the work

. If that looks fine I would be asking for the labour money back at the very least!