Having worked at one of the largest compressor rebuilders I know of for many....many years, I can truthfully say I have never seen nor heard of a cracked head on either an 06D or an 06E Carrier compressor. Both those series compressors are absolutely top notch compressors. I cannot see how an oil related failure could possibly account for a "Cracked Head" as even if a rod should snap and try and push Mr. piston out of the compressor, it would still have to move the valve plate out of the way first.
I have seen a few broken heads on the 06E's due to faulty torque sequencing with a pnuematic impact wrench, but that was found when the now broken head was installed.
Ain't "None" of us as smart as "All" of us..