Such false alarms are common. Often, the "fancy" casino installers used by some brands behave in a similar fashion to trojans, and a alert can be triggered by the pattern of behaviours in the "exe" file. These installers tend to be the very small ones, that when run, connect to the internet and download the "real" casino installer. Since they are so small, they have very little extra code in them that makes it possible to properly check them for legitimacy, so they are matched with the most similar malware signiature on the database.
Many applications also regard ANY casino installer as "malware", even when it shows as a legitimate installer for that brand of software, and the industry only have themselves to blame for this, as this is the result of all the malware tricks used in the past to cajole customers to try out the casinos.