That is a plume heading northwest — the illumination proves it. The illumination also indicates a vertical launch because the sun is not illuminating the underside of the plume, it is illuminating the west side, the leading edge, of the plume. The object creating the plume is heading northwest. If it was headed east, it would be impossible for sunlight from beneath it, coming as it would be from the west, to illuminate the leading edge of the object as it propelled forward. In the video, it is crystal clear that it is not being illuminated from behind, but from in front.
Again, the object leaving the plume is heading northwest.
This is what I thought.
It's pretty clear the contrail is being lighted from below by the Sun below the horizon. That's why there's so much red light.
BTW, no one reported a missile launch the week before either.
The cloud of exhaust vapor is clearly bending around the curve of the Earth along the track of the plane.
In the oldest parts the light getting to the camera has had to travel through more air ~ maybe 50 to 100 miles in fact ~ and this results in a degree of magnification ~ particularly as compared to the parts further East (the ones overhead as the plane is beginning its descent phase into Ontario airport East of LA).
There's no missile here ~ just an airplane.