Why is the second lowest cost silver plan (SLCSP) premium reported as $0 when no advance premium tax credit (APTC) was taken?

In the instructions for Form 8962 (Premium Tax Credit), it says:

If no APTC was paid for your coverage, Form 1095-A, Part III, column B, may be wrong or blank or may report your applicable SLCSP premium as -0-.

My form has it reported as 0. Healthcare.gov provides a tool to lookup your SLCSP in that case. Why is this necessary? I can’t come up with a reason why the column would be wrong. Do they just put 0 as a minor barrier to somebody incorrectly claiming the premium tax credit?