Your correct it was ment to be &&, i didnt take the time to think much about it so even if i had got the && right you would have still have found the reduntent bit after it frown
See i copied the WHILE line above and converted it to a final IF check, its the same code just using IF and || (should have been &&)

The code is in fact completely redundant, I should have just included it before the break.

taking...
while ($fline(%win,$2,%i)) { if ($line(%win,$v1) == $2) { break } | inc %i }
if (($fline(%win,$2,%i)) || ($line(%win,$v1) == $2)) { dline %win $fline(%win,$2,%i) }

to...
while ($fline(%win,$2,%i)) { if ($line(%win,$v1) == $2) { dline %win $fline(%win,$2,%i) | break } | inc %i }

Damn good spotting by the way!