IMO Able Archer '83 was more dangerous. NATO's exercise had many similarities with the activity the USSR expected to see before an attack, as predicted by Operation RYaN. It seems probably that the Soviets sincerely believed that a bolt-out-of-the-blue nuclear attack by the US was within the realm of possibility, which is why RYaN was set up. Those on the US side of the Cold War knew NATO would never perform a surprise attack concealed as an exercise. It'd be maskirovka in the fullest sense, and maskirovka on that scale is not part of the rather sportsmanlike rules of war that the West believed in. Overall, IMO, I don't think NATO ever really understood how genuinely afraid the Soviets were of the United States. We knew we wouldn't strike first or start an offensive war, but the USSR didn't know that. (I think the same thing applies the other way around -- the Soviets did not want to strike first or start a major war, but the Americans thought the USSR planned day and night of the best way to paint the world red.) Anyway, RYaN perceived the NATO exercise as possibly the early stages of mobilizing for an aggressive war.
Perhaps the most important reason why Able Archer brought the world close to war is the fact that there was a semblance of context. Suppose AA really was a cover for starting WW3. The days and weeks leading up to the event, and especially the event itself, gave plenty of evidence that a surprise attack really was in the works. That is, the Soviet leaders would have been hearing about NATO's activities for several days, if not longer. OTOH, the Norwegian rocket happened without context. It was a sudden blip on Russian radar screens. The Cold War was over, and the Russians didn't observe any sort of military buildup. They didn't observe anything at all before the radar return came in. Because there was no context of NATO aggression, the Russians in 1995 would be likely to recognize the signal for what it was, a single rocket launch the details of which were not properly communicated to Russia.
Able Archer, OTOH, had context. NATO was simulating a war, and troop movements, communications, etc. were consistent with preparations for war. As a result, the USSR had a hair trigger. We can be grateful that no one launched a rocket or tried to send bombers into Soviet airspace during Able Archer. Suppose Andropov were woken up at 3 am on some November night with the news that the air defense radars had detected bombers or a missile. He'd been hearing about the military buildup for weeks, particularly in the last week. And now his staff awakens him with news of incoming bombers and possible missile launches? The cheget (nuclear football) would be opened and Andropov would be poring over the various attack options as his staff desperately tried to keep him informed of the latest radar returns. One scenario is that, by skill or by luck, Soviet air defense decided that there wasn't really an attack -- and this would have to happen very quickly, because Andropov might well have had to make his final decision only 15-20 minutes later. The other scenario is that -- remembering that it really did seem like NATO was about to strike -- there many not have been time to make a properly informed decision, under the doctrine of "use it or lose it." In that situation, given that everything pointed to war, Andropov might have even given the launch order.