Confusion arises from the definitions of linear independence, particularly when considering a set of vectors that includes a zero vector or is underdetermined. The key point is that a set of vectors is linearly independent if the only solution to the equation formed by their linear combination equating to zero is the trivial solution, where all coefficients are zero. In the discussed case, the presence of a zero column implies that there are infinitely many solutions, contradicting the notion of linear independence. Thus, while the textbook may suggest the vectors are independent based on the first three variables, the inclusion of a zero vector or an underdetermined system ultimately indicates linear dependence. Understanding these distinctions clarifies the apparent paradox in definitions of linear independence.