another random thought : studs have to be torqued properly , im wondering if they were just screwed in till they stop and then when he tightened the nuts down and fired it the combo of the vibration heat and expansion of the parts caused them to loosen enough that it pulled water into the cylinders .
for that matter it may have only been 1 on each side not properly torqued or backed out enough that once water got in it forced it between cylinders .12:1 compression is a fairly tight piston to combustion chamber clearance and all that water has to go somewhere in a hurry since it cant compress it .
even a bad set of gaskets could cause it if it got bent in 1 corner enough to create a low spot by just 1 water jacket . dont know just a few thoughts i had .
im hoping for his sake that nothing else was damaged such as the rods pistons or crank if there was that much water in it
