I'm trying to get the shipping carrier field from the Sales Order. I've tried loading the Sales Order record and doing:

record.getFieldValue('shipcarrier')
record.getFieldText('shipcarrier')

Both of them return null though. I saw an article in NS Support saying you have to get 'shipcarrier' field on the sublist of items, but that also didn't work.

record.getLineItemValue('item', 'shipcarrier', 1)
record.getLineItemText('item', 'shipcarrier', 1)

All of them return null. When I look at the XML version of the Sales Order page, I see the following on the body of the order:

<shipcarrier>nonups</shipcarrier>

So why can't I get the shipcarrier field value from the sales order? All I need to know by script is whether the carrier is UPS or FedEx in the end.