Grim Speculation

You’re the Head and only judge of a Modern PPTQ. Arielle is playing against Nice. Arielle controls a Liliana Vess and he activates Liliana’s -2 ability, searches and finds a card. She then shuffles her library and puts that card on top of it. Arielle then attacks with a Grim Haruspex, and Nick blocks with a Tarmogoyf. They go to combat damage, both creatures die, then Arielle says “draw for Haruspex” and draws a card immediately. Nice reads Grim Haruspex, points out that the card shouldn’t have been drawn, and calls a judge.

What do you do?

Judges feel free to answer on Judge Apps!

Issue Arielle a Warning for Hidden Card Error. Arielle reveals her hand and Nice chooses one card from there to be put back into the top of Arielle’s library. Remind both players to read their cards carefully.