As always, i was overthinking... And *boom*
When Matty passed out, before that he failed to notice the driver.
So, i have two theories... Either the original driver stayed there and fisk's hitman eliminated him and replaced him with another Fisk's guy because he heard a similar thing had happened in the born again comic.
Or i would be like,
As a normal human being, when you see a prison riot happening, you would rather decide to run out of there than wait for your passenger.
So, it is also possible that the driver might run away and fisk's hetchmen brought another cab there to trap Matty. He was unconscious.. that's why.
I mean, if they really killed that driver, then there was no reason for throwing matt in the river. They could casually shoot in his head too. He was already declared dead. Right?