iPhone rings through Airpods even on silent

Sometimes I use my Airpods to block off noise when I sleep.

The other day, I had my iPhone on silent (via the hardware toggle switch on the side), and it still rang in my Airpods and woke me up in the most cruel way. That caller did NOT have the emergency bypass feature active for them in my Contacts.

What's worse, I specifically went into action center and switched the sound output from Airpods to iPhone speakers, but it disregarded it and blew my eardrums out while I was sleeping. Is this a bug?