Although you may technically be correct - the weapon in this instance hadn't been fired at NATO member territory - there had been instances in which other weapons had been from Syria at individuals in Turkey.
Also, you quoted the original articles where you should have looked at the Protocol to the North Atlantic Treaty on the Accession of Greece and Turkey ttp://tinyurl.com/7vr6auf
Article 1
Upon the entry into force of this Protocol, the Government of the United States of America shall, on behalf of all the Parties, communicate to the Government of the Kingdom of Greece and the Government of the Republic of Turkey an invitation to accede to the North Atlantic Treaty, as it may be modified by Article 2 of the present Protocol. Thereafter the Kingdom of Greece and the Republic of Turkey shall each become a Party on the date when it deposits its instruments of accession with the Government of the United States of America in accordance with Article 10 of the Treaty.
Article 2
If the Republic of Turkey becomes a Party to the North Atlantic Treaty, Article 6 of the Treaty shall, as from the date of the deposit by the Government of the Republic of Turkey of its instruments of accession with the Government of the United States of America, be modified to read as follows:
For the purpose of Article 5, an armed attack on one or more of the Parties is deemed to include an armed attack:
1.
on the territory of any of the Parties in Europe or North America, on the Algerian Departments of France, on the territory of Turkey or on the islands under the jurisdiction of any of the Parties in the North Atlantic area north of the Tropic of Cancer;
2.
on the forces, vessels, or aircraft of any of the Parties, when in or over these territories or any other area in Europe in whicH occupation forces of any of the Parties were stationed on the date when the Treaty entered into force or the Mediterranean Sea or the North Atlantic area north of the Tropic of Cancer.
OK Partner?
It is questionable and contraversial if you are to make it work this way. First, it is huge to claim this jet as a part of occupation forces and second it is stupid to think of the rest of NATO to back Turkey if such a claim to appear with Russia and China on the other side. Claiming it Turkey is risking to get condemned as an agressor inserting ocupation force for an agressive war.
Are you here or there (in Turkey)?
You're absolutely right; thank you for the correction. Still, I don't think it changes the conclusion. Assuming the airplane was over Syria when shot down, the same conclusion applies.