Question: Positive delayed spells and immune checks

[Revils]

On Unit::SpellHitResult

    // Check for immune
   if (pVictim->IsImmunedToSpell(spell))
       return SPELL_MISS_IMMUNE;

   // All positive spells can`t miss
   // TODO: client not show miss log for this spells - so need find info for this in dbc and use it!
   if (IsPositiveSpell(spell->Id))
       return SPELL_MISS_NONE;

   // Check for immune
   if (pVictim->IsImmunedToDamage(GetSpellSchoolMask(spell)))
       return SPELL_MISS_IMMUNE;

so in case of a positive spell there's a check if the victim IsImmunedToSpell but not if ImmunedToDamage while later in DoSpellHitOnUnit, if the same spell is a delayed spell, there are checks for both cases

  // Recheck immune (only for delayed spells)
   if (m_spellInfo->speed && (
       unit->IsImmunedToDamage(GetSpellSchoolMask(m_spellInfo)) ||
       unit->IsImmunedToSpell(m_spellInfo)))
   {
       if (realCaster)
           realCaster->SendSpellMiss(unit, m_spellInfo->Id, SPELL_MISS_IMMUNE);

there's a reason for this different approach or just an exception for !isPositive is missing on recheck immune?