One would need more information about the exact chain of events. Did NORAD call (not necessarily an actual telephone call) Trudeau and say "Mr. Prime Minister,

One would need more information about the exact chain of events. Did NORAD call (not necessarily an actual telephone call) Trudeau and say "Mr. Prime Minister, we have an unidentified object in this location and we recommend to take it down. What is your decision?", "Here's the object and the following options: shoot, follow, let go. What is your decision?", or "Here's the object. What's your decision?" Yes, Trudeau gave the order, but his judgment was undoubtedly influenced by the substance and the manner of the information provided to him and his advisors. It gets more complicated if Trudeau debated the matter with members of his cabinet, as he almost certainly did.