Yes, it was a few of the game-used items that were proven to be fakes. Some were very high end, such as a Joe Jackson Jersey... a rather high profile item.
The vast majority of items in the auction were legit, but the bad uniforms in question were so broadly publicized that to many, it tainted the entire collection. I believe there was an issue with Ty Cobb's dentures as well (you can't make this stuff up). But in reality, most of the general memorabilia was fine, and about 90 - 95% of the game-used lots were as advertised.