You said document everything. So I did. Every single thing.
This happened at a retail job I had a few years ago. Our store manager, I'll call him Greg, had a habit of making verbal instructions and then completely denying he ever said them when something went wrong. Blame would always roll downhill and somehow land on whoever had actually followed his instructions. After watching this happen to three different coworkers in the span of two months I decided I was done being caught in that.
Greg announced at a team meeting that going forward everyone needed to "document everything, I don't want any he said she said, if it's not written down it didn't happen." He was annoyed because two employees had a miscommunication about a shipment and he had to deal with the fallout. Fine. Great actually. I took him completely at his word.
I started documenting everything. Every verbal instruction Greg gave me I would immediately follow up with an email: "just confirming your instruction from 2:15pm today that I should move the seasonal display to aisle 4 rather than aisle 7 as previously planned, please let me know if I have misunderstood." At first he didn't respond to them. Then he started responding with "yes that's correct" because ignoring a written record felt worse to him I guess. I have no idea. But he was building a paper trail against himself one confirmation at a time and he didn't seem to realise it.
About six weeks in he pulled me aside and told me to stop sending so many emails because it was "clogging up communication." I asked him very politely if he could clarify which types of instructions he no longer wanted documented, and whether he wanted that clarification in writing. He stared at me for a long time. He said nevermind. I kept documenting. Never got blamed for a single thing the entire rest of my time at that store.