I was just sitting reading the news on my Samsung Tab S7+ today and my SOS Fall Alert activated on it's own on my Galaxy Watch 4.
I had the option to cancel it or send for help. The cancel option did not work at all, I pressed the X and nothing happend, the watch then went into the countdown mode to contact my designated emergency contact and contacted them. And I now have the little red bell icon on my watch homescreen and can't seem to get rid of it. If I click on it, it only gives me the option to stop sharing location with the person that I want to share location with.
I hope this is a one off, if not, I will be turning this option off, which is a shame, as its a nice option to have.
If there is a positive note out of this, it did work and my SOS Emergency contact called me to see if I was OK.
Just thought I'd share this info in case anyone else has encountered it.