Steps:
Access invalid or inaccessible notebook ID (e.g. https://observablehq.com/d/eb0f603814a2719c)
Expected result:
Page shows 404 Not Found
Actual result:
Page stays blank, shows banner “Welcome. This is live code! Click the left margin to view or edit.”.
Notes:
An initial test actually resulted in an exception loop that spammed analytics and resulted in 100% CPU usage. I wasn’t able to reproduce this case, though.