The number of relays displayed for an onion site can be misleading

Facebook's onion site is a single hop onion, but clicking on the Tor onion icon shows that it is a 6 hop circuit. Roger Dingledine said at Def Con that facebook uses a single hop, here https://youtu.be/Di7qAVidy1Y?t=2135

1. Go to facebookcorewwwi.onion
2. click on the onion icon in the upper left and it should show that it is a 6 hop circuit, even though it should show that it is a 4 hop circuit. Tested on 7.0.6 and 7.5a5.

Trac:
Username: Dbryrtfbcbhgf