AAIB site broken for me currently. Just looking at the track it makes you wonder he was momentarily confused about position on river and trying an approach to the heliport on the wrong section. It doesn't seem likely, but that's what it looks like.
On my walk to work this morning i saw a driver tapping away at his smartphone whilst stationary and then still looking at it as he turned at a junction and drove off. Many distractions in the modern world...