In "Boom Town," which aired during the first season of the new Doctor Who series, our time traveling hero goes to Cardiff in Wales and discovers that a bunch of overweight city planners are building dangerous power plants. For some reason, these city planners are also prone to farting, which they follow up with polite English excuses ("oh dear happens to everyone! must have been the curry!") Turns out, however, that these farters are actually aliens called the Slitheens who because they're too big for the human body suits they're wearing and therefor are always having to let off a little, erm, gas. Though universally loathed by fans, the Slitheens showed up in other episodes, and later starred in a story from the Doctor Who spinoff series Sarah Jane.
Are farts sort of like a wacky gas version of the Danger Drool in Alien? Possibly, though as a counter-example there are Rygel's nervous helium farts in Farscape, which cause him and his human pal Crichton to speak in high voices when they're trapped in a fart-saturated capsule.
Maybe farts don't always equal death, but it's definitely a sign that creators are scraping the bottom of the barrel when conspiracies are unveiled by bad guys who cut the cheese.