My emergency contacts were just called, without me activating the emergency. My phone and watch weren't even near me.
Very inconvenient as my contacts got a call whilst at work and got the fright of their lives.
Which Garmin do you own? Was this during an activity? If not, is it possible that the Power/Light button was inadvertently held down (or by someone else) for 5 seconds? This will trigger the alert and notify your contacts, unless you catch it before the 10-second timer reaches zero.
Then you also have the opportunity to send an "I'm OK" message to those same contacts.

If none of this applies, I suggest reaching out to Product Support.
I own the Venu S2 and only had it for 3weeks. Prior to this watch I had a forerunner 245. I was actually in the kitchen, home alone and both my phone and watch were in the livingroom. It sent an emergency message to people I 'had' as emergency contacts, however, I put them on inactive the minute I got this new watch.
I guess I might have to reach out to Product Support. Thank you very much for your help!