[accrual]

It's a stretch of a tangent, but this reminded me of the Therac-25 incident in which experienced operators of the machine could enter commands too quickly and cause it to enter an unexpected state.

> One failure occurred when a particular sequence of keystrokes was entered on the VT-100 terminal which controlled the PDP-11 computer: if the operator were to press "X" to (erroneously) select 25 MeV photon mode, then use "cursor up" to edit the input to "E" to (correctly) select 25 MeV Electron mode, then "Enter", all within eight seconds of the first keypress, well within the capability of an experienced user of the machine. These edits weren't noticed as it would take 8 seconds for startup, so it would go with the default setup.

https://en.wikipedia.org/wiki/Therac-25