Mismanaged Mimicry Memory

Albert and Nadege are playing in a standard PPTQ. They call you over to the table, and Nadege explains that Albert played Metallic Mimic on his previous turn, which was turn two. Nadege played a land on her turn and passed, and now Albert has played Depala, Pilot Exemplar and Nadege has let it resolve. Albert went to put a +1/+1 counter on his Depala, and when Nadege asked why, he pointed out the Mimic, and they both realized Albert forgot to name a creature type. What do you do?

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Albert receives a Warning for Game Rule Violation, and Nadege a Warning for Failure to Maintain Game State. Making a choice now for a forgotten static ability is one of the fixes available in GRV, so Albert will make a choice now. In addition to the choice, perform a simple backup, as Depala has finished resolving and won’t get a counter now. Back the game up to when Depala was on the stack, let Albert make his Mimic choice, and then give Nadege priority. Depala will resolve and get a counter if Nadege does nothing in response.