I've checked it with your test code. Under Implicit variable access, the variable always pointed as line number 1 when we declare in a cfloop. I think it's working wrong with the conditional loop only. If I loop the argument over the structured loop, it says the correct line for the variable declaration.
FYI that ticket has a low priory because we see that loop type as something you should not use, we even considered once to remove it. Use instead <cfwhile >