Clore's films are credited to Great Portland Productions. Great Portland Street in London has long been home to many film production offices, including some for Hammer.
There is a reference to Phill Jupitus. Phill Jupitus has featured multiple times on the quiz show QI (2003), a show on which Alan Davies is a regular panel member.
The film poster for 'The Yeti Lives' at the start of the episode credits David Wickren for the screenplay. Wickren is an anagram of David Renwick the writer of Jonathan Creek.
Polly is supposedly crunching ice cubes made with neat vodka. However, 80 proof vodka would not freeze in a normal freezer.
Two of the characters are named after mid-20th century US politicians- Reverend Wendell Willkie seems to be named after a Republican who ran unsuccessfully against FDR for the presidency in the 1940 election [lived 1892 to 1944] and D.S. Alben Barkley, called for Harry S. Truman's Vice President from 1949 to 1953 [lived 1877 to 1956]. The hotel where one of the characters is staying is the Schuyler Colfax. He was a 19th century US politician who served as speaker of the House of Representatives, and later Ulysses S. Grant's Vice President from 1869 to 1873, when he left office after being associated with the Credit Mobilier scandal [lived 1823 to 1885].