I would say that comics is happening during the night (or at least not in the middle of day) > therefore the video had to aswell. There is even shadow of something flying, just before that blood splashesh Minsc hands ... so, my gues is that Larian simply recreated this two panels acordingly.
You missed the point. Light is moving in the video as if it's timelapse of a few days, not just one night. The sky texture seems unimportant here, because most of the video looks more like theatre decorations than attempt at realistic detailed depiction. Some people have assumed that the timelapse is the cue for D/N-cycle. And there is no murder in the comic. Only last few seconds depict the comic panel.
