Giant Food Stores complaint: Suspicions of fallacy

I would like to lodge a complaint against head manager Evelyn and the surveillant who issued a written warning against me stated I had missed a single item, Canada Dry Ginger Ale 12pk, in the LaneHawk on 24 April 2021.

A preamble, I know that my work record isn’t spotless. But this stands out to me as nothing short of suspicious. In the time this manager had been out, I had not a single thing reported to me. She comes back towards the tail end of April and only a handful of days later I’m suddenly hit with another warning.

It’s not even really that which irked me, but moreover every time things like this have been brought to me in the past they have never produced any real evidence that I had made the mistake they allege I had made. All they ever say and is ever written is the vague statement to the effect of guy did this thing wrong on this day and year. No transaction ID or time of incident or anything.