ETPM in post #24 --- Great story. Worth more than the last 25 posts I have read! "Moose pee" ingredients essentially caused me to spew a mouthful of coffee all over the room.
VERY interesting comparison between your van and this incident with the Kubota.
A couple of observations:
Your van was probably an in-line-six gasoline type. This Kubota
L3901 is a 3 cyl diesel. So if roughly parallel things happened, you had to conk out the majority of 6 cylinders to stall it while all this guy had to lose was 1 or at most 2 cylinders of his Kubota before it stalled out. I do not see why pouring some oily stuff (be it Moose pee based or not) in the intake of a diesel would do any more or less harm than it did in your gas job unless a sensitive turbocharger is in the picture. If I really thought that was the problem though, I would take off the rocker cover and find a way to rotate the engine while directly lubing the valve stems instead. Probably in the case of this OP's friend/neighbor, the important thing is that things be done in a sensible progression -- check the radiator pressure retention first, then track down the cause if it is dropping, etc. A danger would be if the mechanics working on it fail to consider stuck valves they might do some very unnecessary and expensive things. I can think of several dealers and repair shops who would not always do that in the best interest of the customer. Like for example replacing the head would fix it and cost 25 times as much.
p.s.: if valves are stuck due to overheating of lubricant then the valve seals are almost certain to be shot as well. I would have guessed your van used some oil due to leakage around the valve stems after that fix. Do you remember if that happened?