When writing television story pages, cast and crew lists should make an effort to replicate the cast and crew lists as they appear on episodes as first transmitted. They should never contain information which only appears on IMDb or any other secondary reference material, as the accuracy of such information is often disputable.
In the case of 21st century television, we preference the credits as broadcast over the credits as seen on home video, because we don't want to burden our editors with the responsibility of having to buy home video versions of the stories. We need to choose a standard that all editors will use, and choosing the one that is free means that more editors will be able to comply to the standard.
Crew lists should also not contain information which is widely known to be true but isn't in the credits — such as the fact that Mervyn Pinfield was the associate producer of Planet of Giants, or that Terrance Dicks effectively wrote most of The Seeds of Death.