If you're familiar with their articles, you've probably seen a pattern where articles of ~4 paragraphs come up on the site when a breaking news occurs. You get the sense that they're only concerned with speed rather than accuracy - contents in those 4 paragraphs will change throughout the day, while they'll add about 10 more paragraphs containing some background information and/or interviews. So unless you don't read the "finished version," it's likely that you didn't read the most accurate information.
The way the BBC writers work gives them hardly any time to check facts as well. They're expected to write news tickers, e-mail the news desk about newly written stories, and make a post on Ceefax service as well (hence the 4-paragraph rule). Then they are also expected to harmonize their articles with news from other BBC outlets (e.g. BBC Radio services, BBC News Channel, etc.) so the writers multi-task and constantly have to keep an eye on those services.