Being UK, I was a bit confused about wave and waive and the presence of "off" so I
I understand that when you waive something you forego it or give it up. e.g. I waive my [right to] free coffee. I also understand that a waiver is a document stating that you waive your right...
english.stackexchange.com
and part of the answer is:
The expression being used is wave off, not waive off.
This website from the Indianapolis Speedway explains it quite well:
Wave off – The process by which a team forfeits a qualification attempt. A driver or team can “wave off” an attempt any time before the start of the fourth and final lap in the attempt. If the run is waved off before the car takes the green flag, it does not count as one of the three allowed attempts for that car. Once the green flag is waved to start the attempt, the run counts as one attempt, even if it’s waved off.
If the context isn't auto racing, it's borrowed from auto racing, and has the same meaning.
I am not being pernickety. Just seeking clarification.
Cat