News stories should be brief and answer "5W" questions (who, what, when, where, why). As such, they're supposed to be based on the facts alone, and others should draw their own conclusions from them.
Opinions, on the other hand, are used to put the news stories into context. Journalists are supposed to have more background to the stories than you could learn from just reading the facts (since they're the ones that wrote them). That background can be used to help you interpret those facts.
In this case, an incident happened. BBC put out an opinion piece to tell you why you should care about that incident before they had enough facts to answer all five of those questions. A news story links to that opinion so that they could help you with placing those answers into context.