Perhaps the all-time most unexpected and classic live Oscars moment - seen by millions worldwide, and captured for posterity - is when, at the 1974 Oscars, the great David Niven https://www.themoviedb.org/person/14261-david-niven/discuss/5d604db4924ce5183014fef7 was on stage, giving a presentation, and a streaker came out from the back and ran by!

Here's that moment: https://www.youtube.com/watch?v=EWBc-ir6IFM

I remember seeing that live. It definitely is what everyone was talking about the next day and for some time to come!

PS: The theatre they broadcast from back then certainly is much smaller than the vast venues of recent decades.

Please check out the following list of titles and celebrities I've created TMDb threads for: https://www.themoviedb.org/list/118052