One example involves a female guest playing a bride playing favourites with her sisters. When the groom talks about her youngest sister being absent, she mentions that while she died in a car crash, it gives the occasion a severe case of Mood Whiplash. She then laments that it wasn't her least-favourite sister who was involved in the accident.
Ed Kavalee had a few of these moments with various male guests.
They Changed It, Now It Sucks: For the fourth season, TGYH made a Channel Hop from Ten to Seven. Set changes were made as the shooting location was changed to a pavillion at the Melbourne Showgrounds, and one of the pre-recorded warm up acts was swapped out for a scripted parody piece featuring former cricketer Damien Fleming endorsing all kinds of strange things. Notably, Shaun Micallef and Frank Woodley (arguably among the best performers in the show) did not make appearances at all during the fourth season. A fifth season was planned for 2010, however nothing ever eventuated and the show has not been mentioned by Seven since.
They Just Didn't Care: The ensemble cast of the American remake didn't seem to understand the concept of improv very well, best demonstrated in Mo'Nique's scene when they started correcting her answers for no apparent reason.