Re: Pardon me while I throw-up
"This is a bit of a blinder though, on what must surely be a code path that can be reasonably easily audited."
Never attribute malice to that which could be better attributed to being close to lunchtime or quitting time.
I've hastily reviewed documents at both times, to re-review, to reacquire my train of thought later, and was horrified at what I missed and then had to fix and review a bit farther back. And those were simple things, like mission plans (military) and policies.
Eventually, I narrowed my window of distraction time down and ceased such reviews until the later time period and pursued other items that required my attention. The change, distracting enough to avoid such errors.