In theatrical magic, misdirection is a form of deception in which the performer draws audience attention to one thing to distract it from another.
We do this bad magic to ourselves sometimes. I try and remind my colleagues that when there is a difficult print or new technique, your attention will focus on that and you will possibly miss something obvious. The first time I ran into this screenprinting we printed a difficult process print, we were using two magentas and two cyans to get better tonal range. The photographic image came out great, but the city of Lawrence was not only spelled incorrectly, it was spelled correctly and incorrectly on the same front of the shirt. We counted later that 18 people had seen it without noticing and we were only saved (and only partially saved) when someone came in to pick up a friend for lunch and noticed it.
We got a cool new DTF machine called a Velux and our first real job was for my friends, our Fiftieth (that is 50th.)
An old version of a file and some misdirection and we printed Fifteenth (15th) and luckily someone caught it after just one transfer was applied. We are seeing what serifs and dots reproduce and totally missed the wrong number, that was five of us looking at it that afternoon and all of us missing it. Luckily Monday Morning someone not as excited about the new DTF machine caught the error.
Avoid misdirection, take a deep breathe, maybe show it to someone not involved, and beware.