12 seconds into the video you can see the stoplight change from yellow to red. If you look all the way to the right you can see the white strip signal is horizontal, which tells the train to stop. At 16 seconds it changes to vertical meaning it can go, which makes sense since it should wait a few seconds after for traffic to clear.

It would be good to have clear video of the signal the whole time, but I've seen it in person. The problem isn't the signals.