2006 Kia Sedona Blown Motor

My brother was cleaning the intake manifold of his kia sedona van with intake cleaner that you can buy at any auto parts store. Well for some reason it was really think (gummy) inside and he wound up using about 3/4 of the can to get it all clean using his finger nail. Well after waiting a bit he cranked it up and it exploded. It seems that some castrophic failure happened inside the block and blew 2 holes into the side of the block. The kia dealership says the reason it exploded was due to vapor lock and they found a "substance" on the intake manifold. In my 20 years of working on cars with my fathers 30+ ( he uses to be a mechanic back in the 60's and 70's ) we have never heard nor seen this happen. We have experienced a pressure lock situation where the motor will not turn at all and removing the plugs and putting them back solved the problem. Can the cleaner actually destroy the motor? I can see it on paper but it happened nearly like a bomb. Is this something that you have seen or heard of happening? And what is the rareity of this. Looking at the pieces of AL on the ground under the block it almost appears that it was only 1/4 inch thick wall to begin with and you could also see what I call pockets in the AL chunks that would suggest a poor casting.

thank you