I saw that guy get in the passenger side, which I think was just because he didn't want to walk around. Also, the passenger door is closer to the steering wheel on those trucks than it is on a modern truck. As far as opening the driver's door into traffic, that's less of an issue with a truck with a narrow cab and running boards than on a more modern truck, like the Task Force series. The door wouldn't stick out as far past the fenders.
When my sister was driving my Model A way back when, I had to remind her not to line up the door with the center line of the road, as that would have made the left wheels run on or over the line.
