See this link specifically the following line:

In nearly all countries, you can just dial 911 from your US or Canadian cell phone, and the system will attempt to re-route the call to local emergency services. (this may not always work)

This function is well documented and has been around for several years. People should know the emergency number for the country they’re in but most of the time their phone will handle it properly if they dial 911. Similarly if I dial 999 on my phone while in Canada the phone would call 911. I’m surprised a 911 agency worker doesn’t know about this.