Can someone explain why this filter report [1] indicates that no action was prevented (The account should have been created), but then
(1) MediaWiki says the account does not exist https://fr.wikipedia.org/wiki/Sp%C3%A9cial:Contributions/Ces_accu-sations_graves_qui_seront_rap-port%C3%A9es_%C3%A0_O-range
(2) The CheckUser extension does list the account when showing the list of accounts on an IP.
Thank you.