[3] While in London covering the assassination of Lord Louis Mountbatten for Macquarie in 1979, Riddell caused a security scare and was ejected from Australia House when he was mistaken for a bomber when he was seen with an unscrewed telephone receiver with its wires connected to a small black cassette recorder as he attempted to send a pre-recorded report back to Australia.
[5] He also hosted the documentary series The World Around Us and the local AFL program The Crows Show, despite being an ambassador for Port Adelaide.
[8][9] With Carter, Riddell inaugurated an annual charity fundraiser called the West End Mighty River Run to raise money for Novita Children's Services in 2006.
[10] Riddell briefly returned in radio in June 2012 filling in for Dale Lewis on Triple M Adelaide's Hot Breakfast.
[13] Following the South Australian bushfires of late 2019 and early 2020 which affected the Adelaide Hills and Kangaroo Island, Riddell returned to Seven co-host a special "Book Them Out" edition of SA Weekender to help support the local communities.