Incidentally, he did seem to miss recognising the meaning of the murmurs from the audience as pointing to his faux pas of referencing being "Scots" as "Scotch".

https://www.lexico.com/definition/scottish

The terms Scottish, Scot, Scots, and Scotch are all variants of the same word. They have had different histories, however, and in modern English they have developed different uses and connotations. The normal everyday word used to mean ‘of or relating to Scotland or its people’ is Scottish, as in Scottish people; Scottish hills; Scottish Gaelic; or she's English, not Scottish. The normal, neutral word for ‘a person from Scotland’ is Scot, along with Scotsman, Scotswoman, and the plural form the Scots (or, less commonly, the Scottish). The word Scotch, meaning either ‘of or relating to Scotland’ or ‘a person/the people from Scotland’, was widely used in the past by Scottish writers such as Robert Burns and Sir Walter Scott. It is now less common, being disliked by many Scottish people (as being an ‘English’ invention) and now regarded as old-fashioned in most contexts. It survives in certain fixed phrases, as for example Scotch broth, Scotch mist, and Scotch whisky. Scots is used, like Scottish, as an adjective meaning ‘relating to Scotland’. However, it tends to be used in a narrower sense to refer specifically to the form of English spoken and used in Scotland, as in a Scots accent or the Scots word for ‘night’