Rebuilt engine, bent push rods?
Sorry to hear that, it sucks. I know what you mean, that happened to me when I did a rebuild on my 318. It was my fault and it was caused by my inexperience. I learned all about, "coil bind", I had the head shaved and didn't check for coil bind and I bent the push rods, sucked a valve, put a hole through a piston and scared number two. Whoever you paid for this should make it right. It might not have been coil bind but what you described is exactly what happened to me.
I am sure you will get the right answer here there are alot of truly great gear heads here.