Blue sign here clearly says cycling in this direction is permitted. There's no instruction to use the pavement on the right-hand side of the road, and the pavement on the left ends very soon, making the carriageway the natural option.
Here, a blue directional sign invites cyclists already on the right-hand pavement to cross to the left-hand pavement. However, most people at this point would be cycling on the carriageway and nothing tells these people cycling is permitted on the left-hand pavement.
Approaching the junction where the fatality took place, there's still no indication that cycling on the left-hand pavement is permitted. Nor is there a sign explaining that cycling in this left-hand Games Lane is not permitted (Most of left-hand Games Lanes were open to cyclists). An arrow on the road tells you this lane is for left turns.
Buses typically take this corner a long way from the kerb to allow themselves room to turn, leaving a large gap on their left-hand side and then swinging sharply to their left. It causes a serious hazard to cyclists who can only travel straight ahead and it is difficult to judge if a bus would simply go left or do a u-turn.