As a driver who has driven c. 0.5million miles
I would say that I am very careful about where my passengers alight*. In that instance I would check my mirrors carefully, indicate and if all was clear for a reasonable distance I would pull over to the kerb.
I'd suggest
a. the driver didn't want to lose his place in the traffic.
b. the passenger didn't ask the driver if he could alight but told him he would.
The other point is that the cyclist did not appear to be going fast and the door was flung open in a hurry right in front of him in a moment of total lack of care. It's not as if cyclists are rare in that area - I wonder how many are taking the bikes out because of the rail strike?
*this morning I took a Toyota mechanic out for a test ride, when he wanted to transfer to the back of the car to listen to a noise I made sure I was off the road before he got out.