The gist is, a newspaper vendor, Ian Tomlinson, on his way home from work and moving through the crowded sidewalk, his hands in his pockets, was hit by one of the Metro squad on the leg with an expandable baton, then shoved face-down onto the concrete.
He sat up, got to his feet, and moved on, only to collapse later and die.
The police rationale was that somebody started throwing bottles at them and they decided to move Tomlinson along. What it looks like is that they decided to whack the guy closest to them, who was walking away but not fast enough to suit them, his back turned to the attack, his hands in his pockets. If anybody sees a threat in this guy's demeanor, point it out -- I can't see it.
When the video became public, the officer (Simon Harwood) was suspended, but after a lengthy investigation, which included a botched autopsy and conflicting medical results, the crown declined to prosecute, deeming the chances of a conviction were nil. (The first autopsy said it was a heart attack, the second, internal bleeding secondary to the assault. The pathologist who did the first one was removed from office, as this was only one of several he screwed up.)
Look at the video and decide for yourself. I see armed assault that resulted in manslaughter. Guy was struck, knocked to the ground, and moments later, was dead.
Thanks to Spikybill for the heads-up on this one.