Under the same law, it's illegal to put your brew in the freezer to remove the water (freezing point of water is higher than that of ethanol). No chance of harm in that process, yet still severely punished.
In a clean, well-controlled fermentation vessel, as one might find in an open commercial operation, this is not a problem. But when the process is outlawed, and the producers have to hide, often in places that cannot be biologically sterilized, this problem could occur more often.
But then again, it isn't really about public safety, but about people who want to control other people. Otherwise, the law would mandate adequate fire protection for steam distillers and establish upper limits on non-ethanol fermentation products in frost-distilled products. Either could address the safety concern without outright banning the practice.
In reality, I think the likelihood of a "freezer bust" and consequent punishment is pretty low. Moonshine busts are generally carried out on the state level, and the typical charges are possession and transportation of untaxed spirits.