Valve claims that the complaint was not officially submitted to the "contractually agreed audit and dispute process" and states that the auditor thus refused to consider it. So, what did Activision do? It paid $1,967,796. Yup, that's exactly $424,136 less than the awarded amount. Furthermore, Activision stated it would sue Valve if the company attempted to have the court confirm the total payment due.
Undaunted, Valve is now asking that the court award it the deficient payment and officially close the arbitration process, thus barring Activision from attempting to re-open it. More legal fireworks, it would seem, are about to ensue.