Why won't Revlon give Citigroup back the $900M "accidental" payment?

Mistakes happen in accounting and then they're supposed to get corrected.

Why does this "mistake" smell like money laundering/payoffs?

https://www.reuters.com/article/us-citigroup-revlon-lawsuit-idUSKBN2AG1TJ

Obama SDNY judge https://ballotpedia.org/Jesse_Furman