I checked notables but didn't see if anyone had any guesses as to who Hong Kong pedestrian is.

I have a theory - I'm wondering if this was a hand-off of something between our subject and the guy in blue behind/to the side?

I've enhanced the photo somewhat, and enlarged it.

What jumps out to me is his posture.

His right leg is at a slightly odd angle, as if he's turning awkwardly to his left just on that step. His right arm isn't visible, so where is it?

He seems to be looking at his phone but I would think it would be difficult to see the screen from that distance, especially with the sun high in the sky (could be about noon from the shadows)

The person in blue behind him is verrrrry close to our guy's right side and going by how far apart guy in blue's feet are it seems like he's pausing rather than striding or walking quickly across the street. Notice that guy in blue has his left hand down at his side and he is "not looking" at our subject at all.