Which sounds perfectly reasonable, but it's not necessarily the truth. As another commenter posted here, this has happened before with WoW users [1].
They claimed that they tried and failed to replicate the failure, but anyone who's done any kind of software development knows this is far from conclusive proof.
A post mortem on the logs of the banned accounts is absolutely necessary. If they're not willing to do that, they should at least refund the accounts.
There are multiple versions of Wine out there, and the exact results potentially depend on the user's Linux distro, the exact versions of packages installed, the compiler version it's built with, ... One of the problems Wine developers have is that DRM is often very fragile and sensitive to software changes that are outside their control.
They claimed that they tried and failed to replicate the failure, but anyone who's done any kind of software development knows this is far from conclusive proof.
A post mortem on the logs of the banned accounts is absolutely necessary. If they're not willing to do that, they should at least refund the accounts.
[1] http://www.linuxlookup.com/2006/nov/22/blizzard_unbans_linux...