The Christchurch post was undeniably deleted. This is proof from the database itself, since the public board logs are down. Anyone else with a screenshot of the board log that day will be able to corroborate this. pic.twitter.com/7HWUGPDTtc— 8chan (------) (@infinitechan) September 5, 2019
There is a way to locate specific posts if you have a date, some keywords and a bit of time it can be found.