From the article:
For example, if a person with a $100 bid accepted the invitation to raise his maximum, the system in some cases would immediately raise the bid to $102.50 — even if no one else had bid in the meantime.
Personally, I would be pissed if this happened to me. The good news is, eBay has shown that it will fold like a cheap tent in the case of a major negative outcry (remember last month’s proposed fee increases). Look for this “problem” to be rectified shortly and keep looking in your mailbox for those 50 cent settlment checks.