There's so many different theories on how the law should be interpreted that "far fetched" and "erroneous" are in the eye of the beholder.
For example, a strict originalist may argue that the "right to bare arms" in the constitution only applies to weapons of the day - muskets and cannons. While those who look at the founder's intent would argue that such a right was enshrined so that the people could overthrow the government, thus fully automatic weapons, RPGs, and SAMs are covered. Another group that tries to balance individual rights versus safety would argue that people having the right to a modern military armory may be a tad too unsafe in today's world. So on and so forth, with various sides considering other interpretations to be flat out wrong.