You can ask him yourself, if you want: rms@fsf.org
He replies to almost all emails within a couple of days.
EDIT: He actually answered a very similar question in his reddit AMA [1]:
22. two_front_teeth: Suppose your doctor told you that you needed a medical procedure to survive but that the procedure would require inserting a device inside of your body which ran proprietary software. Would you be willing to have the procedure done to save your life?
RMS: The only way I could justify this is if I began developing a free replacement for that very program. It is ok to use a nonfree program for the purpose of developing its free replacement.
You don't want to have a buggy pacemaker with unencrypted unprotected wireless access.
http://www.theregister.co.uk/2010/07/27/buggy_pacemaker_code...
https://www.softwarefreedom.org/resources/2010/transparent-m...
Moreover I don't feel comfortable using a technology that is owned, developed and maintained exclusively by one company.
In some ways, it's best not to think too hard about this.
If it were open source you, or anyone who was fitted with the pacemaker could look at the rules that control it.
Making _anything_ visible and open to criticism instantly makes its creators more accountable and adds pressure for them to try and be responsible.
Free eyes have lower marginal cost to the consumer than proprietary ones.
If the Oracle suit taught me anything, it's to be careful when using APIs.
"And the issue doesn't really arise for software that goes in a watch or a microwave oven or an automobile ignition system. Because those are places where you don't download software to install. It's not a real computer, as far as the user is concerned. And so, it doesn't raise these issues enough for them to be ethically important."
Source: http://www.gnu.org/events/rms-nyu-2001-transcript.html
He's changed his mind about servers since then, so I wonder if he also has since changed his mind on devices?
> However, if I am visiting somewhere and the machines available nearby happen to contain non-free software, through no doing of mine, I don't refuse to touch them. I will use them briefly for tasks such as browsing. This limited usage doesn't give my assent to the software's license, or make me responsible its being present in the computer, or make me the possessor of a copy of it, so I don't see an ethical obligation to refrain from this. Of course, I explain why they should migrate the machines to free software, but I don't push them hard, because that would be counterproductive.
Sure, he raises that alarm early and often (and in an annoying voice), but he's been right more than once about issues nobody else had considered before.
The first fatalities from software in medical systems were in mid-80's when an X-ray machine gave excess radiation to patients because of a programming mistake. I recall it was an integer overflow.
This issue is more serious than just making fun of RMS's extremist views.
(sorry for the lack of links to sources, I'm sure you can find them if you're interested)