EA gets a cut because they are the publisher nor Crytek, Crysis brand name and franchise is under them. Same with Ubisoft owning the FarCry brand. However EA does not own Crytek, they have a freehand on where to take their next project.

Most common reason due to chargeback from either credit/ debit card or PayPal. The bank or payment institute denies payment to be processed into Steam.

Lots of people use this method to do their scamming on Steam especially from gift trading.

In most cases Steam will just restore the originally traded items or game. However it usually takes time to trace even though Steam have the trading logs since some trades are overly complicated that involves multiple users.

The only course now is for the guy to contact his bank or card issuer to re-authorize all the transactions that was previously made else Steam will take it as a fraudulent purchase or chargebank and disable all those games that he purchased from Steam.