Originally Posted by
klparrot
I actually think the latter was a much bigger no-no. I don't believe they're allowed to take off before the safety briefing is complete. I've been on another flight where we were next in line for takeoff but gave up our spot to another plane because our safety briefing wasn't complete.
In the event of a short taxi and insufficient time to complete the briefing, oxygen and lifevest demonstrations can be performed after take-off and when the seat belt sign has been extinguished as per T.C. regulations.