Code:
on ^*:TEXT:*:?:{
  if (!%flood) {
    set -u5 %flood 1
  }
  elseif (%flood <= 5) {
    inc -u5 %flood
  }
  elseif (%flood > 5) {
    inc -u5 %flood
    window -c $nick | haltdef
  }
}

add an extra inc -u5 and its fine :tongue: