Since the OP still hasn't replied to everyone's simple question about HOW the HELL they let 3 weeks of parts go running at full speed without any inspection checks, I assume they are busy doing something or other. The crux of the issue may be wages I dunno. Someone with the skill and experience to command a $25-35 wage likely isn't going to be the person scrapping by using a 37deg instead of a 45deg chamfer....
Yea I mean I don't know the full details of the situation and who this employee is but if that happened here, I would be firing you. I fired someone for being late everyday and not having good reason to be late and not texting or calling. In fact, at one of my old shops they fired one of the Mill Leads for this exact reason. He scrapped an entire batch of tong plates which are very large steel plates with a bunch of holes. Every single hole was offset by exactly 0.625" meaning that the person didn't properly offset the setup. NOR did that person bother doing a first article inspection which is just common sense.
This wasn't the first time it happened, which is why we fired them. If it is the first time, maybe the person can learn from it and improve but if that person doesn't already have a good track record and a decent bit of company clout then they're getting the axe when they turn $60,000 worth of parts into scrap in a single day.
If your company has situations like that, it is extremely important to resolve them either with training and education or with letting people go if they are a money suck on your company. Employees should make money for the company one way or another.
I;m going to quote everyone's least favorite machinist Titan Gilroy - we need to lift our trade up AND machinists need to take pride in their work. If you can't take pride in what you do then what the hell are you doing?