I can relate. Since this feature was introduced, I've called 911 three times and all 3 times I was unable to hang up due to a bug.
I was riding home on my motorcycle, received a call from a tele-marketer. My bluetooth headset in my helmet automatically picks up on the 2nd ring and I'm trying to hang up and I click the power button a few times and it calls 911...but I'm wearing gloves so I can't hang up. Here's a video:
The other 2 times were unique and a very specific bug. Raise to wake has been the bane of my existence. As I dock the phone in my car which has CarPlay, the screen wakes up and twice my thumb has swiped across the screen right to left activating the camera as I dock it which sends the phone into a complete locked screen...no response at all. On two occasions I tried to reboot the phone using the old method (side button + home) but on iPhone 8, you have to click power up, then down then hold those 2 buttons. well, 911 would be called doing this the old way so now I know it's calling 911 and my screen is still not responding so I have to talk to a person and beg them to hang up on me because my phone is locked up and not responding to taps.
One day, this feature will save my life but I've spoken to 911 3 times in the last 6 months.