I may be wrong, but there is an information firewall between Citadel Securities (the market maker that pays for order flow), and the Citadel LLC (the hedge fund that is bailing out Melvin Capital)
I am not a financial professional, but I am not stupid.
Anyone who believes that 1. this firewall exists, 2. is up to snuff (ie. working like it should), and 3. is not being constantly undermined formally or informally is sorely mistaken.