I was actually in Washington, at the Pentagon, as we were tracking this suspected object.
It is extremely important to know that the efficacy of NORAD is based on the mutual co-operation that we share with the United States and have shared for the last 65 years, so I thank you for asking the question.
It is part of NORAD's process to track objects, including tracking the height of the object. As mentioned, when you have an object at 60,000 feet, it is less of a concern from a population standpoint and from a skies standpoint than an object at 40,000 feet. The object over the Yukon was at about 38,000 feet, which did then pose a risk to the skies. That occasioned the need to shoot it down, which NORAD effectively did.