Redis [QUESTION] In the getNodeByQuery function, why does the counting of missing_keys involve looking up keys in the current database?

When using lookupKeyReadWithFlags() to count missing_keys, the preceding if statement checks for migrating_slot || importing_slot, and the lookup operation explicitly uses the current server's database.

/* Migrating / Importing slot? Count keys we don't have.
 * If it is pubsubshard command, it isn't required to check
 * the channel being present or not in the node during the
 * slot migration, the channel will be served from the source
 * node until the migration completes with CLUSTER SETSLOT <slot>
 * NODE <node-id>. */
int flags = LOOKUP_NOTOUCH | LOOKUP_NOSTATS | LOOKUP_NONOTIFY | LOOKUP_NOEXPIRE;
if ((migrating_slot || importing_slot) && !pubsubshard_included)
{
    if (lookupKeyReadWithFlags(&server.db[0], thiskey, flags) == NULL) missing_keys++;
    else existing_keys++;
}

However, when assigning the importing_slot variable, there is no check to verify whether the hash slot actually belongs to the current node.

 if (firstkey == NULL) {
    /* This is the first key we see. Check what is the slot
     * and node. */
    firstkey = thiskey;
    slot = thisslot;
    n = getNodeBySlot(slot);

    /* Error: If a slot is not served, we are in "cluster down"
     * state. However the state is yet to be updated, so this was
     * not trapped earlier in processCommand(). Report the same
     * error to the client. */
    if (n == NULL) {
        getKeysFreeResult(&result);
        if (error_code)
            *error_code = CLUSTER_REDIR_DOWN_UNBOUND;
        return NULL;
    }

    /* If we are migrating or importing this slot, we need to check
     * if we have all the keys in the request (the only way we
     * can safely serve the request, otherwise we return a TRYAGAIN
     * error). To do so we set the importing/migrating state and
     * increment a counter for every missing key. */
    if (n == myself &&
        getMigratingSlotDest(slot) != NULL)
    {
        migrating_slot = 1;
    } else if (getImportingSlotSource(slot) != NULL) {
        importing_slot = 1;
    }
}