[wideminded]

Also, the trajectory is upward and to the west.

How do you know that the trajectory is toward the west?

[gandalftb]

Perspective is difficult in this video. However, the observer was inland or east of the event. The plume narrows as it passes progressively through clouds that are more brightly lit by the setting sun, therefore higher clouds, therefore it seems that the object is rising in an arc'ed trajectory.

The visual size of the object decreases as it rises, due partially to increased vertical distance. However, the size decreases too much to be explained by vertical gain, so I conclude that the object is traveling away from the observer and flying to the west.

Of course that contradicts an inbound aircraft. Also, aircraft fly relatively level.

The characteristics of the plume are the strongest evidence, its color and density are not that of contrails.