What the standard says
Functionality that can be operated by device motion or user motion can also be operated by user interface components and responding to the motion can be disabled to prevent accidental actuation, except when:
Why it matters
Someone whose device is mounted to a wheelchair cannot shake it.
What a failure looks like
- failsShake-to-undo with no undo button.
How to fix it
- doAdd the equivalent control, and let motion actuation be turned off.
How A11ySignal checks it
manual
No automated rule can judge this criterion, and we will not pretend otherwise. A clean scan does not mean 2.5.4 passes — it means nothing we can measure fails. This one needs a person.