[Judgmentality]

You are really hung up on trying to reconcile that 'disability' has a different meaning in an English dictionary as from a court of law. In different contexts, the word will mean different things. When in doubt, provide additional details to alleviate any confusion - this will vary on a case by case basis.

[tolbish]

The meaning of words will always depend on the context they are used in. Even outside of a court of law, there are still people here who disagree that a person with an occupied hand is still disabled.

That seems like something that will shift towards one or the other as society talks more openly about disabilities.

[microtherion]

I'd probably call that a "hands busy" situation rather than a disability situation, but some of the same computer features may be helpful for both situations.