It was a moment many die-hard Countdown lovers would have given their student loan to see. Rachel Riley, replacement to the inimitable Carol Vorderman on the long-running words and numbers show, pulled out a series of letters from her virtual hat: DTCEIASHF. Heads bent down, pencils were put to paper as each contestant tried to form the longest word. And for one quick-witted, if potty-mouthed, Cambridge University student the eight-letter answer came in a flash of inspiration. "Shitface?" he offered.

Sadly, the powers that be at Channel 4 ruled that, rather than reward Jack Hurst for thinking on his feet, the round of the daytime gameshow would have to be scrapped because the expletive had been let loose, despite many fans arguing that such colouful constructs should merit double points, and the backing of Countdown's oracle, Dictionary Corner's Susie Dent. Dent told presenter Jeff Stelling the term, slang for "rude or obnoxious person" or "drunk person", would have been acceptable. Yet, to mass disappointment – Facebook groups are sure to follow – the station decided it was not suitable and a fresh selection of letters was used.

Although the effort is likely to go down in the annals of classic Countdown moments – up there with the edition in which both contestants arrived at the word "wankers" – many readers may wonder why, with a "D" available, Hurst did not seize the chance to set the Countdown set flashing with the nine-letter "shitfaced".

Countdown was the first show broadcast on Channel 4 when it launched in November 1982, and has become a national institution. It remains to be seen if the scandal of questioning Dent's authority will adversely affect its popularity.

Channel 4 said yesterday: "Countdown is a daytime programme and this particular word was not deemed appropriate for a daytime audience."

At least Hurst, 18, can take comfort in his previous performances: the maths student won eight shows during his stint on the programme last month. He also achieved the highest ever total for the word "octochamp", although it is likely to be his latest performance that will be most lauded by his fellow Cambridge students.