Hellcarver Demon does not exile the cards meant to be played

[Susucre]

Not tested, but code looked like the Demon does not move the cards to exile before allowing them to be played:
8a07ff3#r141543383

[[Hellcarver Demon]]

[github-actions]

Hellcarver Demon - (Gatherer) (Scryfall) (EDHREC)

{3}{B}{B}{B}
Creature — Demon
6/6
Flying
Whenever Hellcarver Demon deals combat damage to a player, sacrifice all other permanents you control and discard your hand. Exile the top six cards of your library. You may cast any number of spells from among cards exiled this way without paying their mana costs.

[jeffwadsworth]

Check this. bbb9382#diff-039594609175f705ac5bc04505929d0b6a57e9cae5c1cb0eeeba5ececa836490