How to fix array index out of bounds exception on Array field in Aggregation

[pmminov (Pablo)]

I'm trying to get the values of a multified with my term aggregation and I'm seeing something odd. I have 2 fields, one is an array and the other is just a string. Both have a keyword field to store the keyword version of the value and a 2nd multifield that has a normalized version of it. I want for my buckets to bring both the key and the normalized version

"industries": {
      "properties": {
        "name": {
          "type": "text",
          "fields": {
            "keyword": {
              "type": "keyword",
              "ignore_above": 256
            },
            "normalized": {
              "type": "keyword",
              "ignore_above": 256,
              "normalizer": "xyz_normalizer"
            }
          }
        }
      }
    },
"representative": {
      "properties": {
        "name": {
          "type": "text",
          "fields": {
            "keyword": {
              "type": "keyword"
            },
            "normalized": {
              "type": "keyword",
              "ignore_above": 256,
              "normalizer": "xyz_normalizer"
            }
          }
        }
      }
    }

I had not much luck with finding a way and resorted to an aggregation term with a script, but this is where it gets strange. The following throws a array_index_out_of_bounds_exception

{
  "size": 0,
  "aggs": {
    "platforms": {
      "terms": {
        "field": "industries.name.keyword",
        "script": "doc['industries.name.keyword']+ ',' + doc['industries.name.normalized']"
      }
    }
  }
}

However if I do it for my other field it works:

{
  "size": 0,
  "aggs": {
    "platforms": {
      "terms": {
        "field": "industries.name.keyword",
        "script": "doc['representative.keyword']+ ',' + doc['representative.normalized']"
      }
    }
  }
}

How do I make my script capable of working for the array value as it does for the plain one?