the real problem is that at Vuaxhall the river is only 500 ft wide
And the St George Wharf tower appears to be less than 100 ft from the river bank, so that would mean that helicopter route H4, which I assume runs along the middle of the river, would be less than 350 ft from the tower. Pilots often can't climb above the tower because of a 1000 ft ceiling due to Heathrow traffic.
Actually the river width at that point looks nearer to 800 ft from the satellite view, but even so, that still means that H4 is less than 500 ft from the tower, and of course a smaller distance from the crane jib. And H4 is a route that the CAA say must be flown "precisely".
So it seems that you can't keep to the "not within 500 ft of anything" rule and keep to the precise route of H4. Or am I missing something?