In his CEO's Corner blog, Steckler wrote, "I apologize to each and every one of you - I realize that security is fundamentally about trust and you have to trust your security provider. We made a mistake here and it won’t happen again."
The update detected over 50,000 clean file samples as being infected. The result was that some users have reported having to restore their systems from backups or reinstalling Windows. More details are available on this forum post, made by Avast!'s CTO Ondrej Vlcek.