I’m not convinced. The amounts of alcohol involved are very small and people with this deficiency are not told to stay away from alcohol no matter what.
I don’t think the comparison with lactic acid is adequate—alcohol is a much more common substance, which is present in small concentration basically everywhere. I just think that the quantity is very small to matter, even with the “local” argument.
So what? It still comes from ethanol. Again, people with this deficiency are not told to stay away from alcohol no matter what.