Why was the Burnley game a low-risk fixture?

It still defies belief that the match against Burnley was categorised as a "low-risk" game by the Safety Advisory Group. Clearly whoever grades games has no input from West Ham fans and doesn't read the papers or go on social media. Yes, a Burnley game would be low-risk normally, but not in the context of recent events. Low-risk meant police did not have to be in the ground. 

There was a large article in the Independent last week about the planned march by the Real West Ham Fans Action Group that was hastily postponed after a meeting with Karren Brady and Sullivan. This also covered the fact that the West Ham Independent Supporters Association still wanted to march and had received threats on Facebook. 

The Evening Standard followed this up with an article on similar lines headlined, "West Ham distance themselves from notorious fan group founded by Inter City Firm members." Saturday's Guardian had a feature headlined, "West Ham fan groups at war after protest march rift", while the Times had a double-page interview with Julian Dicks covering the fans' dissatisfaction with the new stadium and owners. 

The previous week David Gold had been abused by West Ham fans as he left the Swansea stadium. At Liverpool the West Ham away fans displayed that controversial "more damage to the East End than Adolf Hitler" anti-board banner. Then there was the recent release of the club accounts which revealed a £43m profit but less that £2m extra revenue from the new stadium crowds. Every West Ham Facebook and twitter group was talking about the on/off march and there was a lot of anger and frustration that it had been cancelled. 

My daughter couldn't go to the match and I was quite relieved, as it seemed obvious there would be a bad atmosphere and possible trouble. We all knew what it would be like. Even Dr Watson would have probably got the general mood. Why didn't the people who manage the stadium know what was going on?