At Heathrow yesterday, a US-Swedish dual citizen presented his US passport to immigration, as he had forgotten his Swedish one at home.

He went in the non-EEA queue and was initially interviewed like a non-EEA national, but the officer then asked if he held any other nationality, whereby he said he was also Swedish but had forgotten his Swedish passport at home.

The officer asked if he had any evidence of his Swedish nationality, whereby he found (in his bag) his English-language signed and stamped birth certificate from Sweden, which doesn't contain a photograph, but states his nationality as Swedish.

Apparently this satisfied the officer, whereby he stamped his US passport, with the leave stamp saying "Given indefinite leave to enter the United Kingdom" (example below):

[![enter image description here][1]][1]

with a handwritten annotation saying "holder is also an EEA national".

I read in a UK guidance that "indefinite leave to enter" stamps are officially no longer to be used at ports of entry, having been replaced by visa stickers obtained in advance.

That's why I wonder: was this the correct procedure for handling an EEA national without an EEA passport?

If not, what specifically should the person have been given instead? And in the unlikely event of a police or immigration enforcement inspection, would he be OK with what he's got?

Note: picture is an example of what the stamp the traveller got looks like. This happened on 1 feb 2017, and he will now be in the UK for 4 weeks. [1]: https://i.sstatic.net/3moB3.jpg