If it does, I doubt it's because of Toribash itself, it just happened to be the file the virus infected.
That, or it's either more prone to catch the virus because it's a shared file, or it was deleted because it's a shared file.
The latter can be true if your mom's either hypersensitive about virus threats, or doesn't know about these things herself and deletes everything your antivirus program says "may be harmful". I wouldn't doubt an antivirus program flashing an alert about any shared file, including "it may harm your computer".
As for arguments to continue playing the game, they're pretty much the same as with any piece of software with an extensive user base. Thousands of people have downloaded the game, even paid money to the provider, earlier to play the fill version of the game, nowadays for cosmetic features in it. If the program was harmful, whatever the disclaimer (that nobody read anyways) said, there'd be a shitstorm for Nabi studios, one so big that you could buy two computers twice as good with the money you got for the scam.
Simply because if it's a virus (threat) for you, it could be a virus (threat) for everyone else who's downloaded it. Which brings us to the fact that not ever before have I come across anyone's antivirus program saying it's spyware or a virus.